This PDF file contains the front matter associated with SPIE Proceedings Volume 13096, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

We present the current status and future plan of the instruments at the Subaru Telescope. The Prime Focus Spectrograph (PFS) achieved the engineering first light in September, 2022. The installation of the PFS subsystems will be completed in November, 2023, and it is entering the final stage of the commissioning. For the next generation wide-field facility instrument ULTIMATE-Subaru, it successfully passed the preliminary design review and started the detailed design study for the GLAO system in 2022. There are ongoing projects for the facility AO system (AO188) including the upgrades of the deformable mirror and wavefront sensors. In addition, we are discussing implementations of the Nasmyth Beam Switcher, which enables remotely switching the instruments downstream of AO188, for more efficient operation at NsIR focus. As for the visitor instruments, there are a growing number of interests to carry in new instruments, upgrade existing ones, or resume operations of decommissioned instruments as visitor instruments. We are having discussions to better coordinate these demands and develop a future roadmap of NsIR instrumentation including both facility and visitor instruments.

For more than a decade the Paranal Instrumentation programme at ESO has been responsible for the procurement and delivery of the instruments and new infrastructure to the VLT and La Silla observatories. We review the status of the programme, the most recent instruments delivered, with a glimpse into the future. CRIRES+, ERIS, NIRPS have been recently added to the battery of instrument offered, and three major projects: MOONS, 4MOST and SoXS are close to the start of operations, while GRAVITY+ is being developed in an incremental way, with the design and the implementation of the different subsystems proceeding simultaneously. A lessons learned exercise was carried out in 2023. One major change will take place in 2024, with the unification of the Paranal Instrumentation Programme and the ELT instrumentation programs.

The Large Binocular Telescope, with its expansive collecting area, angular resolving power, and advanced optical design, provides a robust platform for development and operation of advanced instrumentation for astronomical research. The LBT currently hosts a mature suite of instruments for spectroscopy and imaging at optical through mid-infrared wavelengths, supported by sophisticated adaptive optics systems. This contribution summarizes the current state of instrumentation, including upgrades to existing instruments and commissioning of second generation instruments now in progress. The LBT is soliciting proposals for next generation instrument concepts, with participation open to consortium members and others interested in participation in the Observatory.

The instrumentation of the Prime Focus Spectrograph (PFS), a next generation facility instrument on the Subaru telescope, is now in the final phase of its commissioning process and its general, open-use operations for sciences will provisionally start in 2025. The instrument enables simultaneous spectroscopy with 2386 individual fibers distributed over a very wide (∼1.3 degrees in diameter) field of view on the Subaru’s prime focus. The spectra cover a wide range of wavelengths from 380nm to 1260nm in one exposure in the Low-Resolution (LR) mode (while the visible red channel has the Medium-Resolution (MR) mode as well that covers 710−885nm). The system integration activities at the observatory on Maunakea in Hawaii have been continuing since the arrival of the Metrology Camera System in 2018. On-sky engineering tests and observations have also been carried out continually since September 2021 and, despite various difficulties in interlacing commissioning processes with development activities on the schedule and addressing some major issues on hardware and software, the team successfully observed many targeted stars as intended over the entire field of view (Engineering First Light) in September 2022. Then in parallel to the arrival, integration and commissioning of more hardware components, validations and optimizations of the performance and operation of the instrument are ongoing. The accuracy of the fiber positioning process and the speed of the fiber reconfiguration process have been recently confirmed to be ∼ 20−30μm for 95% of allocated fibers, and ∼130 seconds, respectively. While precise quantitative analyses are still in progress, the measured throughput has been confirmed to be consistent with the model where the information from various sub-components and sub-assemblies is integrated. Long integration of relatively faint objects are being taken to validate an expected increase of signal-to-noise ratio as more exposures are taken and co-added without any serious systematic errors from, e.g., sky subtraction process. The PFS science operation will be carried out in a queue mode by default and various developments, implementations and validations have been underway accordingly in parallel to the instrument commissioning activities. Meetings and sessions are arranged continually with the communities of potential PFS users on multiple scales, and discussions are iterated for mutual understanding and possible optimization of the rules and procedures over a wide range of processes such as proposal submission, observation planning, data acquisition and data delivery. The end-to-end processes of queue observations including successive exposures with updated plans based on assessed qualities of the data from past observations are being tested during engineering observations, and further optimizations are being undertaken. In this contribution, a top-level summary of these achievements and ongoing progresses and future perspectives will be provided.

Since the start of science operations in 1993, the twin 10-meter W. M. Keck Observatory (WMKO) telescopes have continued to maximize their scientific impact to produce transformative discoveries that keep the U.S. observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided though collaborative partnerships primarily with the Caltech and University of California instrument development teams and through additional collaborations with the University of Notre Dame, the University of Hawaii, Swinburne University of Technology, industry, and other organizations. This paper summarizes the status and performance of observatory infrastructure projects, technology upgrades, and new additions to the suite of observatory instrumentation. We also provide a status of instrumentation projects in early and advanced stages of development that will achieve the goals and objectives summarized in the 2023 Keck Observatory strategic plan. Developed in collaboration with the WMKO science community, the Keck strategic plan sets our sites on 2035 and meets goals identified in the Astro2020 Decadal Survey.

The Southern African Large Telescope (SALT) is a 10-m class fixed-elevation telescope with a primary mirror composed of 91 spherically figured one metre segments. A prime focus tracker assembly carries the spherical aberration corrector (SAC) and two of SALT’s instruments, SALTICAM (the acquisition and imaging camera) and the multi-purpose Robert Stobie spectrograph (RSS). Included in the tracker payload is a fibre-instrument feed, that positions ~45m long fibre cables coupled to the spectrographs in thermal enclosures beneath the telescope. These are the High-Resolution Spectrograph (HRS) and NIRWALS (Near InfraRed Washburn Astronomical Laboratories Spectrograph). The other major undertaking is a custom-built laser frequency comb and precision radial velocity data pipeline for the HRS, due in 2025. A novel RSS slit-mask IFU was recently commissioned, adding optical IFU spectroscopy to SALT’s capabilities. Work is also underway to develop a new red channel to turn the RSS into a dual-beam spectrograph. A study done in 2021 investigated the feasibility of building deployable robotic arms equipped with mini SACs to take advantage of SALT’s huge uncorrected field of view. Lastly, a pre-study is now underway to explore options for replacing the SAC and prime focus payload on the tracker to improve telescope performance and make provision for future instrument development.

IGRINS-2 is a high-resolution, near-infrared spectrograph developed by Korea Astronomy and Space Science Institute (KASI) for Gemini Observatory as a new facility instrument. It provides spectral resolving power of ~45,000 and a simultaneous wavelength coverage of 1.49-2.46 μm. IGRINS-2 is an improved version of IGRINS (Immersion GRating INfrared Spectrometer) with minor optical and mechanical design changes, new detector controllers, and operating software to be fully integrated into Gemini operating systems. Since the project began in early 2020, project key milestones including assembly and pre-delivery performance verification were completed, and delivered to Gemini North in early September, 2023. After the successful post-delivery verification and telescope integration, the first light spectra were acquired in October 2023. We present design changes and upgrades made to IGRINS-2 from the original IGRINS, assembly and alignment procedures, and verification of the instrument requirements. We also report the preliminary results of the system performance tests.

The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, echelle spectrometer that specializes in the discovery and characterization of exoplanets using Doppler spectroscopy. In designing KPF, the guiding principles were high throughput to promote survey speed and access to faint targets, and high stability to keep uncalibrated systematic Doppler measurement errors below 30 cm s⁻¹. KPF achieves optical illumination stability with a tip-tilt injection system, octagonal cross-section optical fibers, a double scrambler, and active fiber agitation. The optical bench and optics with integral mounts are made of Zerodur to provide thermo-mechanical stability. The spectrometer includes a slicer to reformat the optical input, green and red channels (445–600 nm and 600–870 nm), and achieves a resolving power of ∼97,000. Additional subsystems include a separate, medium-resolution UV spectrometer (383–402 nm) to record the Ca II H & K lines, an exposure meter for real-time flux monitoring, a solar feed for sunlight injection, and a calibration system with a laser frequency comb and etalon for wavelength calibration. KPF was installed and commissioned at the W. M. Keck Observatory in late 2022 and early 2023 and is now in regular use for scientific observations. This paper presents an overview of the as-built KPF instrument and its subsystems, design considerations, and initial on-sky performance.

Laser frequency combs, producing a dense grid of equidistant optical emission lines, are considered the best calibration sources for precision astronomical spectrographs. The recently commissioned Near-Infra-Red Planet Searcher (NIRPS), operating at the 3.6m telescope in La Silla, Chile, will be equipped with an astrocomb for the wavelength calibration in the 1200nm – 1850nm range. The astrocomb is based on the electro-optic modulation technology and offers tunability of the full optical spectrum.

A major endeavor of this decade is the direct characterization of young giant exoplanets at high spectral resolution to determine the composition of their atmosphere and infer their formation processes and evolution. We present the implementation and first on-sky results of the HiRISE instrument at the very large telescope (VLT), which combines the exoplanet imager SPHERE with the recently upgraded high resolution spectrograph CRIRES using single-mode fibers. After introducing the global implementation, we will present the status after commissioning and after the first science observing runs. We will, in particular, focus on the performance and th lessons learned during the development, installation and validation.

The Near-InfraRed Planet Searcher or NIRPS is a precision radial velocity spectrograph developed through collaborative efforts among laboratories in Switzerland, Canada, Brazil, France, Portugal and Spain. NIRPS extends to the 0.98-1.8 μm domain of the pioneering HARPS instrument at the La Silla 3.6-m telescope in Chile and it has achieved unparalleled precision, measuring stellar radial velocities in the infrared with accuracy better than 1 m/s. NIRPS can be used either standalone, or simultaneously with HARPS. Commissioned in late 2022 and early 2023, NIRPS embarked on a 5-year Guaranteed Time Observation (GTO) program in April 2023, spanning 720 observing nights. This program focuses on planetary systems around M dwarfs, encompassing both the immediate solar vicinity and transit follow-ups, alongside transit and emission spectroscopy observations. We highlight NIRPS’s current performances and the insights gained during its deployment at the telescope. The lessons learned and successes achieved contribute to the ongoing advancement of precision radial velocity measurements and high spectral fidelity, further solidifying NIRPS’ role in the forefront of the field of exoplanets.

Hector is a new optical integral field spectrograph (IFS) instrument built by Astralis - Australia’s Astronomical Instrumentation Consortium. Hector was commissioned on the Anglo-Australian Telescope (AAT) in 2022. In 2023 it began a 15,000-galaxy IFS survey of nearby z< 0.1 galaxies. The high fill-factor imaging fibre bundles ‘hexabundles’ of the type used on the SAMI instrument, have been improved and enlarged to cover up to 27-arcsec diameter. The aim is to reach 2 effective radii on most galaxies. Hector has a unique and novel robotic positioner that compensates for varying telecentricity over the 2-degree-field of the AAT to recoup the light loss and correct the focus across the field. Hector has 21 hexabundles over that 2-degree field feeding both the new Hector spectrograph (Spector) and existing AAOmega spectrograph. The new dual-arm Spector spectrograph has the highest spectral resolution of any large IFS nearby galaxy survey of 1.3 Angstrom. This is key to enable higher order stellar kinematics to be measured on a larger fraction of galaxies and to link those galaxies to the large-scale environments in which they form. A data reduction pipeline has been developed and is producing science-quality galaxy cubes and the first internal data release is now being used for science.

The Visible Integral Field Replicable Unit Spectrograph (VIRUS), the instrument for the Hobby Eberly Telescope Dark Energy Experiment (HETDEX), consists of 78 replicated units, each with two integral field spectrograph channels. VIRUS reached the full complement of spectrographs in 2021 and has been undertaking the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The VIRUS design takes advantage of large-scale replication of simple units to significantly reduce engineering and production costs of building a facility instrument of this scale. With VIRUS being 156 realizations of the same spectrograph, this paper uncovers the statistical variations in performance of these units along with effective strategies for specifying large batches of components. Results of delivered spectrograph component performance compared to statistical batch specifications are presented. Based on variations in performance of individual spectrograph components, throughput curves are simulated for 156 VIRUS spectrograph channels. Once delivered, each unit is paired with a fiber bundle and throughput measurements are made on sky using twilight flats. We compare throughput variance from on-sky measurements of 140 channels to the simulated throughputs. We find that the variation in throughput matches that predicted by modeling of the combined individual component performance. The average overall throughput of VIRUS measured on-sky and the variability in unit performance meets specification for the HETDEX survey, which is now complete. This paper presents VIRUS as a proof of concept that massively replicated instruments provide a viable solution to scaling up instruments for the next generation of large surveys and telescopes.

The VIRUS2 instrument is a new fiber-fed multiplexed integral field spectrograph consisting of 6 units, each with 4 spectral channels, to provide large on-sky area coverage coupled with broad spectral coverage. VIRUS2 will be a new facility instrument on the McDonald Observatory 2.7 m Harlan J Smith Telescope with 2.33 arcminute field of view and 2.5 arcsecond spatial sampling. The instrument employs a novel beam-switch module within the fiber feed to split the light into the 4 spectral channels covering 370-930 nm at R~2000, while achieving a very compact and highly stable instrument. The design of VIRUS2 emphasizes stability and careful calibration, with scrambling in the beam-switch module, compact spectrograph format, and tight thermal control. This is the first time such measures have been employed at moderate spectral resolution. In this paper, we provide an overview of the instrument and the build status of the 24 spectrographs, detector system, integral field units, and telescope interface. VIRUS2 is funded by NSF and deployment will start in late 2024.

Liger is a next-generation near-infrared (0.81 - 2.45 μm) integral field spectrograph (IFS) and imaging camera for the W. M. Keck Observatory (WMKO) adaptive optics (AO) system. The instrument concept originated by coupling designs from WMKO AO instruments and the future Thirty Meter Telescope IRIS spectrograph. Liger is designed for the Keck I telescope to operate behind the upcoming Keck All-sky Precision Adaptive optics (KAPA) system. The imaging camera sequentially feeds an IFS that makes use of slicer assembly for the coarsest sampling (75 mas and 150 mas per spaxel) and lenslet array (14 mas and 31 mas per spaxel) for diffraction-limited sampling. The imaging camera makes use of off-axis parabolas and a Hawaii-2RG detector to achieve a 14 mas/pixel plate scale and 20.5"×20.5" field of view. The IFS offers a range of spectral resolving power of R=4,000 { 10,000 and yields large fields of view for an AO-fed IFS. Liger will enable new science by providing enhanced capabilities, including higher spectral resolving power, access to shorter wavelengths, and larger fields of view than any current or planned ground- or space-based IFS system. Liger will be able to unlock previously inaccessible science across a wide range of the cosmos, such as dark matter substructure, supermassive black holes, the Galactic Center, exoplanet atmospheres, and the time-variable Solar System. We present the overall design of the Liger subsystems and review unique science drivers.

The 10.4m Gran Telescopio Canarias (GTC) was designed to be a versatile telescope, able to serve a wide scientific community. To this aim, various focal stations have been equipped, including a Cassegrain, two Nasmyth foci, and four folded-Cassegrain stations. This allows an ambitious instrumentation plan to be developed. We present the latest developments and plans, with emphasis on the most relevant and innovative features. They include: new detectors and cryogenic (pulse tube) systems for the main GTC instruments, the migration of the HiPERCAM imager to a dedicated focus with an ad-hoc rotator; the commissioning of the single-conjugated AO system for the GTC; the preparation to host in the Coudé room a fiber-fed UV and optical spectrograph which aims at a 10 cm s⁻¹ radial velocity precision; and the plan for the future instruments, which include the upgrading of the adaptive optics system and the development of an imager and spectrograph covering simultaneously the optical and near-infrared domains.

We present here the ongoing initial design for Ocotillo, a new fiber optic spectrograph being designed and built for the Apache Point Observatory 3.5m. Ocotillo is an fiber-fed optical spectrograph, with an interchangable front end allowing either a close-packed IFU with a 20 arcsecond field of view or a 16 robotic positioner system with integral field units on each positioner. Ocotillo, the new intermediate resolution spectrograph for the ARC 3.5m at Apache Point Observatory, provides a much needed update to the optical spectroscopic capabilities of this important mid-sized telescope. With a 9 arcminute field of view, the 3.5m creates opportunities for studying targets across the field as well as focusing efforts on more local central objects where spatially resolved spectroscopic coverage can reveal details of physical processes.

The current suite of instruments is comprised of a wide field optical imager, two optical spectrographs (a low resolution long slit and an echelle), two infrared instruments (a spectrograph and an imager/Fabry-Perot spectrometer), and a high-speed optical time-domain camera photometer.

4MOST is a new high-multiplex, wide-field spectroscopic survey facility under construction for ESO's 4m-VISTA telescope at Paranal, Chile. Its key specifications are: a large field of view of 4.4 square degrees, a high multiplex fibre positioner based on the tilting spine principle positioning 2436 science fibres, 1624 fibres going to two low-resolution spectrographs (R = λ/Δλ ~ 6500), and 812 fibres transferring light to the high-resolution spectrograph (R ~ 20,000). The instrument is entirely completed and is being shipped to Paranal Observatory, Chile in the first few months of 2024. Commissioning will take place summer 2024 with full operations expected to start early 2025. An overview will be given of instrument capabilities, the planned, and the unique operational scheme of 4MOST.

The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is a new facility instrument being designed in close partnership with the upcoming facility adaptive optics (AO) system at Gemini-North observatory called GNAO. GIRMOS will carry out high angular resolution (0.83 – 2.4 µm) imaging and multi-object integral field (0.95 – 2.35 µm) spectroscopy within GNAO’s two arcminute field-of-regard. GIRMOS consists of an imager and four identical deployable integral field spectrographs with a multi-object AO system that provides an additional image quality improvement for each spectrograph over GNAO across the full field. We present the final design overview of GIRMOS, which will be entering the construction phase in 2024 with an expected delivery in 2027. GIRMOS is a pathfinder for future extremely large telescope instrumentation that requires high angular resolution, highly multiplexed spectroscopy.

Arrayed waveguide gratings (AWG) have gained attention as promising integrated spectrographs for ground-based telescopes, airborne applications, and spaceborne instrumentation due to their low mass, diffraction limit characteristics, thermal stability, and robustness against vibrations and misalignment. The Potsdam Arrayed Waveguide Spectrograph (PAWS) is a cross-dispersive instrument based on an integrated photonic spectrograph (IPS) that is optimized for the astronomical H-Band and was designed and developed by innoFSPEC at the Leibniz Institute for Astrophysics Potsdam (AIP). The main element is a second-generation AWG that is fibre coupled and works as a first dispersive element. To work as an IPS, the dispersed light of the AWG is sampled at the output facet and magnified by a microscope objective. The light is then fed into a free-space optical system housed in a cryostat working at 140 K. An afocal relay re-images the exit pupil of the microscope into the plane of a cross-dispersive element containing a diffractive grating. Subsequently, an objective focuses the resulting echellogram on a Teledyne 2k × 2k H2RG near-infrared array working at 80 K. To validate the functionality of the system, different light sources have been used. A tunable laser source generated an echellogram through frame stacking. Furthermore, the cross-dispersed output of a supercontinuum source and of an in-house developed frequency comb system were recorded under varying input conditions of the AWG, successfully achieving first light laboratory measurements. Throughout multiple cycles and measurements of the instrument, several parameters and characteristics were identified, providing opportunities for optimization to enhance the instrument’s performance and facilitate the miniaturization of future iterations. In this manuscript, we will provide a concise overview of the PAWS instrument, the preliminary results of laboratory measurements, and lessons learned to improve the future iterations of the next generation near-infrared cross-dispersed integrated photonic spectrograph. PAWS represents a pioneering demonstration of an astronomy optimized AWG chip, showcasing the advantageous capabilities of integrated photonic spectrograph.

The Orbiting Configurable Artificial Star (ORCAS) mission in collaboration with the W. M. Keck Observatory (WMKO) is poised to deliver near diffraction limited observations in visible light. The ability to conduct such observations will enable significant scientific discoveries in fields related to Active Galactic Nuclei (AGN), Dark Energy, Flux Calibration, the High Redshift Universe, Exoplanets, and the Solar System. The ORCAS team has successfully completed three primary mission development goals to enable such observations. The performance demonstration with the ORCAS Keck Instrument Demonstrator (ORKID) captured arguably the highest resolution image at visible wavelengths from a large (10 meter) segmented telescope on the ground to date. High resolution AO imaging of the galaxy UGC 4729 in Natural Guide Star (NGS) mode was performed by locking onto a foreground asteroid passing nearby, which simulated an observation with a moving guide star validating post processing capabilities and demonstrating how regions unreachable by NGS and LGS could be explored. Additionally, the ORCAS team has successfully locked onto a laser source onboard the Laser Communications Relay Demonstration (LCRD) and closed the adaptive optics loop to perform near diffraction limited imaging at 1550 nm with the Keck 10 meter, the first demonstration of such capability with a large segmented telescope. All of these results validate the feasibility of the ORCAS mission. Following these accomplishments, ORCAS will be strongly positioned to propose a full-scale mission to upcoming opportunities.

WST – Widefield Spectroscopic Telescope: We summarise the design challenges of instrumentation for a proposed 12m class Telescope that aims to provide a large (>2.5 square degree) field of view and enable simultaneous Multi-object (> 20,000 objects) and Integral Field spectroscopy (inner 3x3 arcminutes field of view), initially at visible wavelengths. For the MOS mode, instrumentation includes the fiber positioning units, fiber runs and the high (R~40,000) and low (R~3,000 - 4,000) resolution spectrographs. For the MUSE like Integral Field Spectrograph, this includes the relay from the Telescope Focal Plane, the multi-stage splitting and slicing and almost 150 identical spectrographs. We highlight the challenge of mass production at a credible cost and the issues of maintenance and sustainable operation.

FIRST (Fibered Imager foR a Single Telescope instrument) is a post-AO instrument that enables high-contrast imaging and spectroscopy at spatial scales below the diffraction limit. FIRST achieves sensitivity and accuracy through a unique combination of sparse aperture masking, spatial filtering by single-mode fibers and cross-dispersion in the visible. On-sky commissioning data taken with the instrument installed on the SCExAO platform at the 8-m Subaru telescope show the detection of several stellar companions, including two binary systems with an angular separation of 0.6 λ/D (11mas). Even at such a close separation, FIRST delivers information on the companion spectrum, providing valuable constraints on the stellar parameters, such as the effective temperatures and surface gravity. As a spectro-interferometer fed by a highly effective AO system such as SCExAO, FIRST offers unique capabilities in the context of the spectral characterization of close companions. The discussion concludes with insights into the future of the FIRST instrument, with the move to visible photonic technologies and further advancements in the instrument's capabilities to detect newly formed exoplanets.

A Photonic Lantern (PL) is a novel device that efficiently converts a multi-mode fiber into several single-mode fibers. When coupled with an extreme adaptive optics (ExAO) system and a spectrograph, PLs enable high throughput spectroscopy at high angular resolution. The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system of the Subaru Telescope recently acquired a PL that converts its multi-mode input into 19 single-mode outputs. The single mode outputs feed a R~4,000 spectrograph optimized for the 600 to 760 nm wavelength range. We present here the integration of the PL on SCExAO, and study the device performance in terms of throughput, field of view, and spectral reconstruction. We also present the first on-sky demonstration of a Visible PL coupled with an ExAO system, showing a significant improvement of x12 in throughput compared to the use of a sole single-mode fiber. This work paves the way towards future high throughput photonics instrumentation at small angular resolution.

We present results from development of a photonic Quantum-Inspired Imager (QI2) providing source reconstruction below the optical/NIR diffraction limit through atmospheric turbulence without adaptive optics. Our group has demonstrated a photonic spatial mode sorter quantum-sensing device in practice — a photonic lantern — with capabilities in both spatial and spectral diversity, as well as future extensions to polarization sensitivity. Our team has developed high-efficiency photonic lantern mode-sorting/multiplexing devices fabricated in optical fibers. Our proposed passive imaging system is therefore based on three main innovations: (i) photonic lantern spatial mode sorters with spatial and spectral diversity, (ii) atmospheric blur removal enabled by mode-/wavelength-resolution, (iii) quantum-inspired image reconstruction techniques.

The Multi Object Optical and Near-infrared Spectrograph (MOONS) instrument is the next generation multi-object spectrograph for the Very Large Telescope (VLT). The instrument combines the high multiplexing capability offered by 1000 optical fibres deployed by individual robotic positioners with a novel spectrograph able to provide both low- and high-resolution spectroscopy simultaneously across the wavelength range 0.64μm - 1.8μm. Powered by the collecting area of the 8-m VLT, MOONS will provide the astronomical community with a world-leading facility able to serve a wide range of Galactic, Extragalactic and Cosmological studies. This paper will provide an updated overview of the instrument and report on its performance during the final stage of integration testing. The next stage of the instrument is on site-assembly into the telescope, ready for first light and full commissioning. MOONS will be starting science operations in October 2025.

In May 2024, the SOAR Adaptive-Module Optical Spectrograph (SAMOS) was installed at the SOAR 4.1 meter telescope in Cerro Pach´on, Chile. We discuss the instrument commissioning process, the integrated system performance, and first light results. SAMOS is a digital micromirror device (DMD)-based multi-object spectrograph and imager designed for use with the SOAR adaptive module ground-layer adaptive optics system. SAMOS covers 4000 Å to 9500 ˚A with a 3′ ×3′ field of view. The unique layout of the instrument allows for the spectroscopic and imaging channels to operate in parallel. While integrating spectral targets, the observer can simultaneously perform photometry on the remainder of the field, improving the spectro-photometric calibration compared to a conventional multi-object spectrograph. In SAMOS, the DMD is used as a reconfigurable slit mask that redistributes slits near-instantaneously. The spectrograph operates in a low resolution and high resolution mode with R∼2500 and R∼6500 respectively for a 0.33′′ slit width. We discuss the work completed during initial commissioning of the instrument and report the first light results.

We present an update to the 2024 Magellan Infrared Multi-Object Spectrograph (MIRMOS). MIRMOS is a wide-field (13′ × 3′) near-infrared (0.89-2.4 μm) spectrograph with either a multiobject or integral-field mode. MIRMOS is designed to perform either faint-object distant-object spectroscopy, or high-signal-to-noise transmission spectroscopy of exoplanet atmosphere. MIRMOS is designed to deliver a spectral resolution of > 3, 400, delivering the Y, J, H, and K bands over four Hawaii H2RG detectors. The slit robot allows the observer to create 92 slits or a 26′′ ×20′′ integral-field unit can be swapped in. In this proceeding, we describe changes since the last SPIE conference.

The Gemini Observatory's instrument program supports breakthrough research in areas such as extrasolar planets, time-domain astrophysics and cosmology, all while providing the best possible competitive instrumentation suite given technological and budget constraints. This paper offers a broad overview of Gemini's instrumentation program, highlighting achievements, challenges, and strategies. We report on the status of the currently offered facility instruments and AO systems at each telescope. The facility instrument program offers a robust suite of capabilities with broad applicability, handling the largest share of science return and thus concentrating the largest development efforts. In 2023 we completed the commissioning of GHOST at Gemini South, a high-resolution optical echelle spectrograph, and in 2024 we completed the commissioning of the near-infrared high-resolution spectrograph IGRINS-2 at Gemini North. We are currently integrating SCORPIO, a simultaneous 8-channel, optical to infrared camera and spectrograph for Gemini South focused on time domain astronomy and Rubin Observatory follow-ups. There has been continued progress on the design of the community-led multi-IFU MOAO spectrograph, GIRMOS, which will operate with GNAO, the future adaptive optics facility at Gemini North, currently in its design stage. Additionally, the visiting instrument and instrument upgrade programs support more unique observing modes, which might have a narrow scope but potentially high scientific impact. As part of the upgrades program, in 2024 we completed the commissioning of two NIR integral field units for the Gemini North workhorse spectrograph GNIRS. In addition, we summarize here the progress and next stages of the radial velocity spectrograph MAROON-X, the performance of the speckle imagers at each site, the ongoing improvements to the GeMS MCAO system at Gemini South, and the upgrades of GPI prior to its relocation to Gemini North.

The Thirty Meter Telescope (TMT) will host three science instruments at first light: IRIS (InfraRed Imaging Spectrograph), WFOS (Wide Field Optical Spectrograph), and MODHIS (Multi-Objective Diffraction-limited Highresolution Infrared Spectrograph). IRIS is a workhorse imager and spectrograph coupled to the Narrow-Field InfraRed Adaptive Optics System (NFIRAOS) to exploit the gains possible when working at the diffraction limit on an extremely large telescope. It has an imager field of view of 34 by 34 square arcseconds, and the integral field spectrograph supports a variety of spaxel scales and fields of view at resolutions between 4000 and 10,000. MODHIS, also working behind NFIRAOS, is focused on exoplanet science will deliver precision radial velocity measurements at a spectral resolution of 100,000 for a single object. WFOS is the workhorse optical multi-object imaging spectrograph. It has an 8 by 3 square arcminute field of view and is capable of targeting almost 100 objects at once with resolutions between 1500 and 5000.

HISPEC (High-resolution Infrared Spectrograph for Exoplanet Characterization) is an infrared (0.98 to 2.46 microns) cross-dispersed, R=100,000 single-mode fiber-fed diffraction-limited echellette spectrograph for the Keck II telescope’s adaptive optics (AO) system. MODHIS (Multi-Objective Diffraction-limited High-resolution Infrared Spectrograph) shares similar specifications as HISPEC while being optimized for TMT’s first-light AO system NFIRAOS. Keck-HISPEC, currently in full-scale development and slated for first light in 2026, and TMTMODHIS, currently in conceptual design phase, will provide increasingly compelling science capabilities from exoplanet atmosphere characterization through both transit and direct high-contrast spectroscopy, to detection and mass measurements through infrared precision radial velocity (RV). The science cases include the precise RV measurements of stars orbiting the Galactic Center, Solar System studies, and the chemodynamical history of nearby dwarf galaxies and the galactic halo.

We describe the development status of the first generation of science instruments for the Giant Magellan Telescope (GMT) and the very broad range of first-light capabilities that they will deliver. The first-generation suite includes: visible and infrared spectrographs delivering a wide range of spectral resolution; an infrared, diffraction-limited imager; and a visible to near-infrared, extreme adaptive optics coronagraphic imager and spectrograph. G-CLEF, a visible light echelle designed for broad scientific use and for precision radial velocity measurements, is in fabrication. Instruments in the final design phase as of this publication, include: GMACS, a high-throughput, wide-field, multi-object spectrograph; GMTNIRS, a near- to thermal-infrared echelle spectrograph utilizing silicon immersion gratings to achieve a very compact design that delivers a fixed-format spectrum from 1-5μm in a single exposure; GMTIFS, a diffraction-limited, near-infrared, integral-field imager and spectrograph; and GMagAO-X, which has internal deformable mirrors coupled with a coronagraph to deliver extreme-AO resolution, high contrast imaging and spectroscopy of extrasolar planets, including nearby potentially habitable terrestrial worlds in reflected light. The first-generation suite also includes a robotic fiber-feeding system called MANIFEST, currently in conceptual design, that enables spectroscopy over the 20 arcmin field of view of the telescope and can feed GMACS, G-CLEF, and future near-IR spectrographs intended to work at atmospheric spatial resolutions. We also discuss the visible and infrared cameras (called ComCam and AOTC, respectively) that will be used for alignment, verification, and commissioning of the active and adaptive optics modes of the telescope, as well as enable early science and outreach activities.

We present the preliminary design of GMagAO-X, the first-light high-contrast imager planned for the Giant Magellan Telescope. GMagAO-X will realize the revolutionary increase in spatial resolution and sensitivity provided by the 25 m GMT. It will enable, for the first time, the spectroscopic characterization of nearby potentially habitable terrestrial exoplanets orbiting late-type stars. Additional science cases include: reflected light characterization of mature giant planets; measurement of young extrasolar giant planet variability; characterization of circumstellar disks at unprecedented spatial resolution; characterization of benchmark stellar atmospheres at high spectral resolution; and mapping of resolved objects such as giant stars and asteroids. These, and many more, science cases will be enabled by a 21,000 actuator extreme adaptive optics system, a coronagraphic wavefront control system, and a suite of imagers and spectrographs. We will review the science-driven performance requirements for GMagAO-X, which include achieving a Strehl ratio of 70% at 800 nm on 8th mag and brighter stars, and post-processed characterization at astrophysical flux-ratios of 1e-7 at 4 lambda/D (26 mas at 800 nm) separation. We will provide an overview of the resulting mechanical, optical, and software designs optimized to deliver this performance. We will also discuss the interfaces to the GMT itself, and the concept of operations. We will present an overview of our end-to-end performance modeling and simulations, including the control of segment phasing, as well as an overview of prototype lab demonstrations. Finally, we will review the results of Preliminary Design Review held in February, 2024.

The discovery of a fair sample of Earth-analogues (Earth 2.0’s), i.e. rocky, Earth-mass exoplanets orbiting a Solar-type star in that host star’s habitable zone, and a subsequent search of evidence of bioactivity on those Earth 2.0’s by the detection of biogenically produced molecules in those exoplanetary atmospheres, are two of the most urgent observational programs in astrophysics and science in general. To identify an Earth 2.0, it is necessary to measure the reflex motion radial velocity amplitude of the host star at the 10 cm/sec level, a precision considerably below that which is currently achievable with existing instruments. The follow-on project to search for the biomarkers in an Earth 2.0’s atmosphere may require an effective planet/star contrast of 10-10, again well below the currently achievable level. In this paper, we discuss technical innovations in the implementation of the GMT-Consortium Large Earth Finder (G-CLEF) spectrograph that will enable these observational objectives. We discuss plans to operate G-CLEF at the Magellan Clay telescope with the MagAO-X adaptive optics system and subsequently with GMagAO-X at the Giant Magellan Telescope (GMT).

MANIFEST is a fibre-fed positioning system designed to enhance the capabilities of the 24.5m Giant Magellan Telescope (GMT). For the first light 14 arcmin field-of-view (FoV), MANIFEST will use the GMT’s current planned instruments: G-CLEF (an echelle resolution spectrograph) and GMACS (low/mid resolution spectrograph). MANIFEST will connect with these existing optical spectrographs and offer three multiplexing and deployable integral field unit (IFU) modes. In the future, a full 20′ FoV mode will be offered using a near-infrared spectrograph. Its unique features include high multiplexing, deployable IFUs, increased spectral resolution, and the potential for simultaneous observations with multiple instruments. MANIFEST will support four key science cases: galactic archaeology, dynamical masses of local dwarf galaxies, galaxy stellar kinematics, and unveiling the reionisation epoch with Lyα. In addition, simulations comparing Starbugs, pick-and-place, Starspines, and Theta-phi positioning technologies determined that the pick-and-place robotic solution offers optimal performance, reliability, and adaptability while minimising technical risk with off-the-shelf components. MANIFEST’s advanced capabilities will ensure efficient survey operations and maximise scientific output, making it a pivotal tool for the GMT.

MICADO is a first light instrument for the Extremely Large Telescope (ELT), set to start operating later this decade. It will provide diffraction limited imaging, astrometry, high contrast imaging, and long slit spectroscopy at near-infrared wavelengths. During the initial phase operations, adaptive optics (AO) correction will be provided by its own natural guide star wavefront sensor. In its final configuration, that AO system will be retained and complemented by the laser guide star multi-conjugate adaptive optics module MORFEO (formerly known as MAORY). Among many other things, MICADO will study exoplanets, distant galaxies and stars, and investigate black holes, such as Sagittarius A* at the centre of the Milky Way. After their final design phase, most components of MICADO have moved on to the manufacturing and assembly phase. Here we summarize the final design of the instrument and provide an overview about its current manufacturing status and the timeline. Some lessons learned from the final design review process will be presented in order to help future instrumentation projects to cope with the challenges arising from the substantial differences between projects for 8-10m class telescopes (e.g. ESO’s VLT) and the next generation Extremely Large Telescopes (e.g. ESO’s ELT). Finally, MICADO's expected performance will be discussed in the context of the current landscape of astronomical observatories and instruments. For instance, MICADO will have similar sensitivity as the James Webb Space Telescope (JWST), but with six times the spatial resolution.

The Mid-Infrared ELT Imager and Spectrograph (METIS) will be one of only three 1st-generation science instruments on the 39m Extremely Large Telescope (ELT). METIS will provide diffraction-limited imaging and medium resolution slitspectroscopy from 3–13 microns (L, M, and N bands), as well as high resolution (R≈100,000) integral field spectroscopy from 2.9–5.3 microns. Both imaging and IFU spectroscopy can be combined with coronagraphic techniques.

After the final design reviews of the optics (2021) and the entire system (2022), most hardware procurements have started. In this paper we present an overview of the status of the various ongoing activities. Many hardware components are already in hand, and the manufacturing is in full swing in order to start the assembly and testing of the subsystems in 2024 toward first light at the telescope in 2028/29. This rather brief paper only provides an overview of the project status. For more information, we refer to the detailed instrument paper which will be published soon.

The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs ([U]BV, RIZ, YJH) providing a spectral resolution of ∼100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 μm with the goal of extending it to 0.35-2.4 μm with the addition of an U arm to the BV spectrograph and a separate K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Modularity and fibre-feeding allows ANDES to be placed partly on the ELT Nasmyth platform and partly in the Coudé room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature’s fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of almost 300 scientists and engineers which include the majority of the scientific and technical expertise in the field that can be found in ESO member states.

HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450 nm to 2450 nm with resolving powers from 3500 to 18000 and spatial sampling from 60 mas to 4 mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade. The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this paper, we provide an overview of the instrument's capabilities, details of recent technical changes during the red flag period, and an update of sensitivities.

MOSAIC is the Multi-Object Spectrograph (MOS) for the 39m Extremely Large Telescope (ELT) of the European Southern Observatory (ESO), with unique capabilities in terms of multiplex, wavelength coverage and spectral resolution. It is a versatile multi-object spectrograph working in both the Visible and NIR domains, designed to cover the largest possible area (∼40 arcmin²) on the focal plane, and optimized to achieve the best possible signal-to-noise ratio on the faintest sources, from stars in our Galaxy to galaxies at the epoch of the reionization. In this paper we describe the main characteristics of the instrument, including its expected performance in the different observing modes. The status of the project will be briefly presented, together with the positioning of the instrument in the landscape of the ELT instrumentation. We also review the main expected scientific contributions of MOSAIC, focusing on the synergies between this instrument and other major ground-based and space facilities.

The Daniel K. Inouye Solar Telescope, with its 4m aperture, is the largest telescope for observations of the Sun, and is currently in its Operations Commissioning Phase. During this phase of the project, the five DKIST first light instruments, the Visible Broadband Imager (VBI), the Visible Spectro-Polarimeter (ViSP), the Diffraction-Limited Near-Infrared Spectro-Polarimeter (DL-NIRSP), the Cryogenic Near-Infrared Spectro-Polarimeter (Cryo-NIRSP) and the Visible Tunable Filter (VTF) are used in selected modes to acquire scientific data. We provide an overview of the DKIST instrumentation system and its inherent flexibility. We further report on lessons learned during commissioning, and present sample data products.

The Visible Tunable Filter Instrument (VTF) is a 2D imaging spectropolarimeter for high spatial and spectral resolution solar observations in the visible light. It will be operated at the world’s largest solar telescope, the 4m aperture Daniel K. Inouye Solar Telescope (DKIST) in Maui, Hawaii, USA. The VTF is designed and constructed by the Leibniz-Institut f¨ur Sonnenphysik (KIS) with support from the Istituto ricerche solari Aldo e Cele Dacc`o (IRSOL), the Max-Planck-Institut f¨ur Sonnensystemforschung (MPS) and the National Solar Observatory (NSO). KIS started integrating and commissioning the VTF at the DKIST in January 2024. VTF is based on two large Fabry-P´erot etalons (FPIs) acting as spectral filters. The field of view of 1 arcmin combined with a spectral accuracy well below 1 picometer leads to a clear aperture (CA) of 250 mm, an allowed cavity error smaller than 3 nm RMS over the CA, a microroughness below 0.4 nm RMS and a required cavity stability of ±100 pm over one hour. Therefore, the world’s largest tunable etalons for imaging applications had to be built. With these etalons, VTF will be able to drive solar science for the next decades. In this paper we describe the overall design and specifications of the VTF-FPIs. The first etalon was completely assembled and commissioned in the lab in 2023. We present the main characteristics as measured in the laboratory and demonstrate the dynamic response probed by the integrated metrology system.

We advocate for the development of a ground-based network of robotic instruments provisionally called ngGONG to maintain critical observing capabilities for synoptic research in solar physics and for the operational space weather forecast. ngGONG will consist of 6 geographically-distributed stations, with longitudes and weather patterns selected to provide nearly continuous observations of the Sun. ngGONG instruments will include: spectropolarimeters for precise measurements of vector magnetic fields at multiple heights in the solar atmosphere; an instrument for line-of-sight Doppler velocity measurements required for studies of the solar interior and farside; rapid narrow-band images; sun-as-a-star instruments; and tunable Hα imager and limited coronagraph capabilities to monitor the violent ejecta of magnetized plasma from the Sun’s atmosphere and determine coronal magnetic topologies and plasma properties. We will discuss the requirements for such an observing system, and present its conceptual design.

SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) is the next-generation, diffraction-limited, thermal infrared, fully cryogenic, coronagraphic exoplanet spectrograph and imager for W.M. Keck Observatory. SCALES is fed by the Keck II Adaptive Optics bench. Both modes use common fore-optics to simplify the optical design and have individual detectors, which are JWST flight spares. The imager mode operates from 1 to 5 microns with selectable narrow- and broadband filters over a field of view 12.3 arcseconds on a side, and the integral field spectrograph mode operates from 2 to 5 microns with both low and mid spectral resolutions (R∼ 100 to R∼ 7500) over a field of view 2.15 arcseconds on a side. The diamond-turned aluminum optics, most of which are already delivered, with the rest being fabricated, provide low distortion, low wavefront error, and high throughput for all modes. The slicing unit, located behind the lenslet array, allows SCALES to reach heretofore unheard-of spatially-resolved spectral resolution for exoplanet and disc observations from the ground with a coronagraphic integral field spectrograph. The SCALES consortium includes UC Observatories, CalTech, W.M. Keck Observatory, the Indian Institute of Astrophysics, and the University of Durham, with over 40 science team members. We report on the overall design and project status during its ongoing fabrication phase, which started in early 2023.

ULTIMATE-Subaru is the next-generation facility instrument program of the Subaru Telescope which will extend the existing Subaru’s wide-field survey capability to the near-infrared wavelength. The ULTIMATE-Subaru instrument suite includes Ground-Layer Adaptive Optics (GLAO) and wide-field near-infrared instruments, aiming to provide ∼0.2 arcsec image size at K band (2.2 μm) over 20 arcmin diameter field of view at the Cassegrain focus. The planned first light instrument is a Wide-Field Imager (WFI), which covers a 14 × 14 square arcmin field of view from 0.9 to 2.5 μm in wavelength. GLAO and WFI are currently in the final design phase, aiming to start the commissioning observations at the telescope in 2028. In parallel to the development for ULTIMATE wide-field instruments, there are ongoing activities to develop a narrow-field wide-band spectrograph (NINJA) together with a Laser Tomography AO system (ULTIMATE-START) utilizing the Adaptive Secondary Mirror and the Laser Guide Star Facility being developed for the GLAO system. In this presentation, an overview of the ULTIMATE-SUBARU instruments, their current status, and future prospects will be presented.

MAVIS, the Multi-Conjugate Adaptive Optics Assisted Visible Imager and Spectrograph, is the world’s first facility-grade visible MCAO instrument, currently in the final design phase for ESO’s VLT. The AO system will feed an imager and an integral field spectrograph, with 50% sky coverage at the Galactic pole. MAVIS has unique angular resolution and sensitivity at visible wavelengths, and is highly complementary to both JWST and ELTs. We describe both instruments in detail and the broad range of science cases enabled by them. The imager will be diffraction-limited in V, with 7.36 mas per pixel covering a 30” FOV. A set of at least 5 broad-band, 3 medium-band and 16 narrow-band filters will provide imaging from u to z. The spectrograph uses an advanced image slicer with a selectable spatial sampling of 25 or 50 mas to provide integral field spectroscopy over a FOV of 2.5′′ × 3.6′′, or 5′′ × 7.2′′. The spectrograph has two identical arms each covering half the FOV. Four interchangeable grisms allow spectroscopy with R=4,000 to R=15,000, from 370 – 935 nm.

The National Astronomical Research Institute of Thailand, together with the Institut d’Optique Graduate School and Centre de Researche Astrophysique de Lyon, has been developing the Evanescent Wave Coronagraph (EvWaCo) a new kind of Lyot coronagraph that uses a lens and prism placed in contact as its focal plane mask. By the principle of frustrated total internal reflection, EvWaCo enables an achromatic rejection and ability to collect the light from the star and the companion. An EvWaCo prototype equipped with adaptive optics will be installed at the Thai National Telescope as an on-sky demonstrator. This demonstrator will work on a 1.2 × 0.8 m² elliptical sub-aperture of the Thai National Telescope to reach a raw contrast of 10⁻⁴ at 3λ/D over the wavelength range [600 nm, 900 nm]. The completed optical design contains all the essential light path channels in high contrast imaging fitted inside a 960 mm×960 mm optical breadboard, namely the guiding camera channel, companion channel, star channel, and wavefront sensing channel. We also show the results of the tolerancing and straylight analysis.

The ORCAS Keck Instrument Demonstrator (ORKID) is a visible-light diffraction-limited camera that was installed behind the WMKO Keck II AO system in the fall of 2022. Its primary purpose is to act as a pathfinder instrument for adaptive optics-fed visible-light imaging at Keck, with consideration for upcoming AO upgrades and future possibilities. ORKID is diffraction-limited down to 650nm and can operate with millisecond frame rates, enabling frame selection and frame registration in post-processing. Here we provide an overview of the commissioning of the instrument and describe its on-sky performance. Using Keck’s current AO deformable mirror, and its Shack-Hartmann and pyramid wavefront sensors, we are able to achieve images with point-spread function cores of 15-17 milliarcseconds FWHM. We report here on early observations obtained within the first year of operations and we provide a gallery of scientific objects of interest with ORKID, as a preview for future capabilities.

iLocater is a new, near-infrared, extreme precision radial velocity (EPRV) spectrograph under construction for the dual 8.4m diameter Large Binocular Telescope (LBT). The instrument uses single-mode fibers (SMFs) injected with adaptive optics for illumination. We present the integration process for the spectrograph and cryostat systems, and the laboratory performance testing that has been completed. Testing has included optical performance characterization at ambient and cryogenic temperatures, assessment of cryogenic thermal control of the system (80-100K) at sub-mK level, and instrument detector performance (an H4RG-10). The optimized spectrograph and cryostat system will be delivered to the LBT in 2024.

Of late adaptive optics coupled compact spectrometers have been much discussed in the literature as an inexpensive means to obtaining very high resolving power (R ~ 100,000 or higher) spectroscopy on large telescopes. The Palomar Radial Velocity Instrument (PARVI), fitting in shoebox-sized space, is the first such instrument on sky and is designed to carry out JH band radial velocity measurements while coupled via single mode fiber transport to an extreme AO system, as well as an electro-optic modulation generated laser frequency comb. In this presentation we discuss the instrument, its current performance, and describe some of the special challenges involved in achieving robust operation at the diffraction limit.

Diffraction-limited spectrographs are key instruments for upcoming large telescopes thanks to their compact sizes that do not scale with telescope diameter and stable point spread functions (PSFs) that are conducive to precise radial velocity (RVs) measurements. A challenge to achieving sub meter-per-second RVs with diffraction-limited spectrographs that does not show up in the RV error budgets of their seeing-limited counterparts, is “differential limb coupling”, which we define as a preferential coupling of one side of a star’s limb over the other. This effect can result in a more blue- or red-shifted stellar spectrum being coupled into a single-mode fiber due imperfect centroiding of the star on the fiber that differs between each RV measurement. This effect is exacerbated when the star is faster rotating and more resolved by an optical system, and can become significant when coupling to single-mode fibers due to their sensitivity to source position on the fiber. In this paper we quantify the RV amplitude of stellar differential limb coupling, and show that the effect can have a significant impact on next generation adaptive-optics (AO) fed spectrographs on large aperture telescopes if uncorrected. We apply these calculations to HISPEC on Keck and MODHIS on TMT and estimate that for 1 mas pointing errors, the RV error term for a star 0.5 mas in diameter rotating at 2 kms⁻¹ would be 1 ms⁻¹and 7.7 ms⁻¹, respectively. We present several design strategies that we expect would reduce the differential limb coupling effect to varying degrees.

MARVEL is a new state-of-the-art facility at the Mercator Observatory (La Palma, Spain) targeting high precision radial velocity measurements. The facility consists of an array of four 80-cm telescopes feeding a single stabilized high-resolution echelle spectrograph. It will provide essential ground-based RV follow-up on transit measurements by previous and upcoming space missions with an RV precision of 1 m/s. This precision requires simultaneous wavelength calibration monitoring on a reliable wavelength reference calibration source. The MARVEL calibration system will be powered by a continuum white light source spanning the target wavelength range of 380-950 nm, and both a ThAr hollow-cathode lamp and a Fabry-P´erot etalon, whose light will be used as a wavelength reference. The light from the continuum source will be divided for use in spectral flat fielding, and for the illumination of the Fabry-P´erot etalon. The wavelength comb of transmission peaks produced by the etalon will be tracked against the hyperfine lines of rubidium, for continuous evaluation of residual etalon drift. Furthermore, the ThAr lamp will serve as an absolute reference for the etalon spectrum. Optical fiber switches will select one of the three calibration sources, as well as transport the light to its destination: the spectrograph, the science fibers at the focus of each telescope, or to a flux monitoring system. In this contribution, we describe the MARVEL wavelength calibration system and the strategy that will be deployed to maximize calibration precision and long-term stability.

RISTRETTO is a visible high-resolution spectrograph fed by an extreme adaptive optics (AO) system, to be proposed as a visitor instrument on ESO VLT. The main science goal of RISTRETTO is to pioneer the detection and atmospheric characterisation of exoplanets in reflected light, in particular the temperate rocky planet Proxima b. RISTRETTO will be able to measure albedos and detect atmospheric features in a number of exoplanets orbiting nearby stars for the first time. It will do so by combining a high-contrast AO system working at the diffraction limit of the telescope to a high-resolution spectrograph, via a 7-spaxel integral-field unit (IFU) feeding single-mode fibers. Further science cases for RISTRETTO include the study of accreting protoplanets such as PDS70b/c through spectrally-resolved H-alpha emission, and spatially-resolved studies of Solar System objects such as icy moons and the ice giants Uranus and Neptune. The project is in the manufacturing phase for the spectrograph sub-system, and the preliminary design phase for the AO front-end. Specific developments for RISTRETTO include a novel coronagraphic IFU combining a phase-induced amplitude apodizer (PIAA) to a 3D-printed microlens array feeding a bundle of single-mode fibers. It also features an XAO system with a dual wavefront sensor aiming at high robustness and sensitivity, including to pupil fragmentation. RISTRETTO is a pathfinder instrument in view of similar developments at the ELT, in particular the SCAO-IFU mode of ELT-ANDES and the future ELT-PCS instrument.

Precise and accurate wavelength calibration of spectrographs is essential for key science cases, e.g. the search for extrasolar planets, a possible variation of fundamental constants and the direct observation of cosmic expansion. A crucial tool for this are laser frequency combs (LFCs), directly linking the accuracy of atomic clocks to optical laser lines. However, strong material dispersion and large spectral separation from the established infrared laser oscillators so far prevent the use of LFCs for spectrograph calibration in the blue and UV part of the spectrum. At OHP/SOPHIE, we demonstrated for the first time the calibration of an astronomical spectrograph using an astrocomb in the ultraviolet spectral range below 400nm. Key technology used were nano-fabricated, periodically-poled waveguides in lithium niobate photonic chips, fed by either a robust infrared electro-optic comb generator or a chip-integrated microresonator comb. In an end-to-end test, we could demonstrate stable and accurate LFC-based spectrograph calibration, showcasing a viable path towards precision wavelength calibration of spectrographs in the ultraviolet, crucial e.g. for the future ELT/ANDES.

An ultra-compact optical spectrograph (~43x16x13cm) is developed using a new optical arrayed waveguide technique based on waveguide spectral lenses (WSL). The WSL is an evolved version from the arrayed waveguide grating design can achieve simultaneous spectral dispersion and image focusing onto the detector plane at designed distance. Despite its compact size, the instrument maintains high optical throughput and provides a wide range of spectral resolution (R~200-2000 at 600-950 nm). The spectrograph's design and the results of laboratory testing will be reported.

We report on the status of Henrietta, a new near-infrared low-resolution (R ∼ 200) spectrograph for the 1-meter Swope telescope at Las Campanas Observatory in Chile. Henrietta is uniquely designed to perform transmission spectroscopy of tens of exoplanet atmospheres per year across a wide bandpass and routinely reach the photon noise limit on a nightly basis. Henrietta is currently at Carnegie Observatories, where it is undergoing assembly and optical alignment, as well as spectrophotometric testing to identify Henrietta’s spectrophotometric noise floor. Upon finishing assembly and testing in Summer 2024, Henrietta will be shipped to Las Campanas Observatory where it will begin commissioning. In this talk, I will describe Henrietta’s science mission, its overall design, the results of current testing, its goals for commissioning and future opportunities for collaboration.

The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument is a novel high-contrast direct imaging facility that was recently delivered to the Turkish 4-m DAG telescope, with first light anticipated by the end of 2024. In a nutshell, PLACID consists in a fore-optics coronagraphic intermediate stage platform, installed in-between the TROIA XAO system and the DIRAC HAWAII-1RG focal-plane array. The PLACID project, led by a consortium of Swiss Universities contracted by the Atatürk University Astrophysics Research and Application Center (ATASAM), has passed the Delivery Readiness Review (DRR) milestone in September 2023, and was delivered to ATASAM campus facilities in March 2024. The PLACID commissioning activities with the calibration light source at the summit, on the DAG telescope Nasmyth platform, are foreseen to take place this fall, with first light scheduled to take place before the end of the year. When on-sky, PLACID will be the world’s first “active coronagraph” facility, fielding a customized spatial light modulator (SLM) acting as a dynamically programmable focal-plane phase mask (FPM) coronagraph from H- to Ks-band. This will provide a wealth of novel options to observers, among which software-only abilities to change or re-align the FPM pattern in function of conditions or science requirements, free of any actuator motion. Future features will include non-common path aberrations (NCPA) self-calibration, optimized coronagraphy for binary stars, as well as coherent differential imaging (CDI). We hereby present the delivered PLACID instrument, its current capabilities, and Factory Acceptance commissioning results with relevant performance metrics.

We have undertaken the development of high-efficiency and wide spectral coverage grisms for MOIRCS, the near-infrared imager and multi-object spectrograph at the Subaru Telescope. Our prior medium-resolution gratings, incorporating Volume Phase Holographic (VPH) gratings, offered very high efficiency at their peak. However, their narrow transmission curves significantly limited their scientific application, especially in the MOS mode. In response to the demand for better medium-dispersion grisms from the community, we developed new high-sensitivity and wide-spectral-coverage grisms (“LightSmyth grisms”) for the J & H windows in 2019. It was a great success, with significant improvement on both peak efficiency and the wide bandwidth coverage. Following this achievement, we embarked on the development of a comparable medium-dispersion grism for the K-band (“VB-K grism”), incorporating our proprietary Volume-Binary (VB) grating. The fabrication was completed by the summer of 2023. The basic performance test inside the dome confirmed its excellent performance as planned. The first scientific use by open-use observers was achieved in March 2024. A more detailed on-sky performance evaluation is scheduled this summer.

The LSST Camera is a complex, highly integrated instrument for the Vera C. Rubin Observatory. Now that the assembly is complete, we present the highlights of the LSST Camera assembly: successful installation of all Raft Tower Modules (RTM) into the cryostat, integration of the world’s largest lens with the camera body, and successful integration and testing of the shutter and filter exchange systems. While the integration of the LSST Camera is a story of success, there were challenges faced along the way which we present: component failures, late design changes, and facility infrastructure issues.

The Keck Wide Field Imager (KWFI) is a 1-degree field of view imager optimized to take advantage of the UV performance of the W.M. Keck Observatory located atop Mauna Kea in Hawaii. The project is an international collaboration between Swinburne University, ANU, AAO-Macquarie, Caltech, UC Observatories, and W.M. Keck Observatory. KWFI fills the 8m-class capability gap for deep, blue wide-field imaging and rapid-response follow-up necessary for many science cases, including cosmic reionization, transient astronomy at all wavelengths and messengers, and space mission main science aims. The instrument has a high-throughput, UV-sensitive design with an all-fused silica 4-lens element corrector system that operates from 300 – 1000 nm and achieves 0.4” 80% encircled energy diameter rms over the FOV within each photometric band. In 2022, we reported on the conceptual design of the imager that includes fast (~10 s) filter exchange of its 600 mm narrowband and broadband filters, fast (seconds) image processing and source identification, and CCD and CMOS detectors. More recently, the team has advanced the development of a Deployable Secondary Mirror (DM2), which will work with KWFI. The DM2 is a 1.4-meter lightweight, remotely deployable hexagonal secondary mirror to allow fast switching between KWFI and any Cassegrain or Nasmyth Instruments to enable rapid spectroscopic follow up of identified sources. We report here on the DM2 conceptual design, progress on the imager design, testing of the prototype filter exchange mechanism, and the interface of KWFI and the DM2 with the 30-year-old Keck Telescope.

First scientific operation and performances of the Javalambre Panoramic Camera (JPCam) are presented in this paper. JPCam, deployed on the 2.6m large field-of-view Javalambre Survey Telescope (JST250) at the Observatorio Astrof´ısico de Javalambre (OAJ), is a 1.2 Gpixel camera conceived to perform the Javalambre Physics of the Accelerated Universe Astrophysical Survey (J-PAS). J-PAS in an unprecedented photometric sky survey of several thousand square degrees of the northern sky in 56 optical bands, 54 of them narrow-band filters (145 Å FWHM). The innovative designs of the J-PAS instrument and filter system has been optimized to accurately measure photometric redshifts for galaxies up to z∼1 and to study stellar populations in nearby galaxies. As a result, J-PAS will provide a low-resolution spectroscopy for hundreds of millions of other galaxies. The data set produced by this survey will have a unique legacy value, allowing a wide range of astrophysical studies. To this aim, JPCam is equipped with a mosaic of 14 large format 9.2k x 9.2k, 10μm pixel, low noise detectors from Teledyne-E2V, providing an unvignetted Field of View of 3.4 square degrees with a plate scale of 0.2267′′/pix. Its filter unit admits 5 filter trays, each mounting 14 filters corresponding to the 14 CCDs of the mosaic and allowing all the J-PAS filters to be permanently installed. To optimize image quality during the observations, the position of the JST250 secondary mirror and JPCam focal plane are maintained optically aligned by means of two hexapod systems. To perform this task, JPCam includes 12 auxiliary detectors, 4 for autoguiding and 8 for image quality control through wavefront sensing. JPCam commissioning was successfully completed and first scientific operation started in summer 2023. This paper shows JPCam on-sky operation and first J-PAS Science Verification results, demonstrating fulfilment of the main J-PAS scientific requirements.

Large field-of-view rapid sky surveys are pivotal methodologies for research in time-domain astronomy. The project entitled ”Antarctic Time Domain Astronomical Optical Observational Array Based on Drift Scanning CCD Technology”, also known as the Antarctic Tianmu Plan, is based in Antarctica and comprises an assemblage of numerous small wide-field optical telescope systems. This expansive array covers a sky area of 10,000 square degrees. Each wide-field optical telescope unit is fitted with a low noise drift scanning CCD camera, facilitating rapid observations without the necessity of moving parts within the telescope system. The advantageous clear polar night conditions of Antarctica are employed to enable repeated and continuous wide-area observations, providing an optimal environment for the monitoring of transient events. A prototype of the Antarctic Tianmu Program was constructed from 2020 to 2022 and subsequently dispatched to the Zhongshan Station in Antarctica for installation, debugging, and operational observation in concurrence with the 39th scientific research vessel at the culmination of 2022. This manuscript primarily presents the quality of raw images and limiting magnitudes acquired at varying exposure times, observational results encompassing photometry precision, and the long-term stability of the system operation during the initial year of observation.

The LSST Camera is the sole instrument for the Vera C. Rubin Observatory and consists of a 3.2 gigapixel focal plane mosaic with in-vacuum controllers, dedicated guider and wavefront CCDs, a three-element corrector whose largest lens is 1.55m in diameter, six optical interference filters covering a 320–1050 nm bandpass with an out-of-plane filter exchange mechanism, and camera slow control and data acquisition systems capable of digitizing each image in 2 seconds. In this paper, we describe the verification testing program performed throughout the Camera integration and results from characterization of the Camera’s performance. These include an electro-optical testing program, measurement of the focal plane height and optical alignment, and integrated functional testing of the Camera’s major mechanisms: shutter, filter exchange system and refrigeration systems. The Camera is due to be shipped to the Rubin Observatory in 2024, and plans for its commissioning on Cerro Pachon are briefly described.

SOXS (Son Of X-Shooter) is the new ESO instrument that is going to be installed on the 3.58-m New Technology Telescope at the La Silla Observatory. SOXS is a single object spectrograph offering a wide simultaneous spectral coverage from U- to H-band. Although such an instrument may have potentially a large variety of applications, the consortium designed it with a clear science case: it is going to provide the spectroscopic counterparts to the ongoing and upcoming imaging surveys, becoming one of the main follow-up instruments in the Southern hemisphere for the classification and characterization of transients. The NTT+SOXS system is specialized to observe all transients and variable sources discovered by imaging surveys with a flexible schedule maintained by the consortium, based on a remote scheduler which will interface with the observatory software infrastructure. SOXS is realized timely to be highly synergic with transients discovery machines like the Vera C. Rubin Observatory. The instrument has been integrated and tested in Italy, collecting and assembling subsystems coming from all partners spread over six countries in three continents. The first preparatory activities in Chile have been completed at the telescope. This article gives an updated status of the project before the shipping of the instrument to Chile.

The Muztage-Ata One-point-nine-three-meter Synergy Telescope (MOST) is a novel equatorial telescope currently being constructed in China. Spectroscopy of bi-Channel with UlTra-wide band and high flUx for MOST (SCUTUM) serves as one of the first-light instruments and adopts a modified FOSC type design with two channels. The design incorporates a shared catadioptric collimator followed by separate refraction cameras in each channel, where in between filters and grisms are inserted into the optical path through two rotating wheel units. The instrument converts the F/8 beam from the telescope to a nearly F/4.3 beam. The spectroscopy of SCUTUM can be performed in the wavelength range 310-1000nm in one exposure, offering various choices of grisms and slits with resolution ranging from 250 to 7500. The theoretical monochromatic RMS spot sizes are expected to be between 0.04′′ and 0.26′′. To optimize total throughput, SCUTUM employs high-efficiency optical elements, coatings, and sensitivity-enhanced detectors within its operational band. The overall transmission from the collimator to the detector is anticipated to exceed 20% at 330nm and surpass 40% at wavelengths above 355nm when operating in R≤3000 mode. The designed weight of this instrument amounts to approximately 280kg. The instrument is currently planned to be assembled in the Institute laboratory in September and to be commissioned on MOST in 2025.

ProtoPol is a medium-resolution echelle spectro-polarimeter initially conceived as a prototype instrument of the currently under development M-FOSC-EP (Mt. Abu Faint Object Spectrograph and Camera-Echelle Polarimeter) instrument - a two-channel multimode instrument which is currently being designed for PRL 1.2m and 2.5m telescopes at Mt. Abu. Though ProtoPol was initially conceived to evaluate the development methodology of M-FOSC-EP with commercially available off-the-shelf components, it was later elevated to the level of a full-fledged back-end instrument for PRL telescopes. ProtoPol was designed on the concept of echelle and cross-disperser gratings to record the cross-dispersed spectra in the wavelength range from 390 to 940 nm with a resolution (λ/δλ) in the range of 7000-8000. ProtoPol has been successfully developed and commissioned on PRL 1.2m and 2.5m telescopes since December 2023, and a variety of observations are being carried out for instrument characterization and scientific purposes. The design and development methodology of ProtoPol with complete off-the-shelf components offers a cost-effective way to develop spectro-polarimeters with such resolutions for small aperture (2-3m) telescopes around the world with a shorter development period.

SHARK-NIR is an instrument providing high-contrast coronagraphic imaging, dual band imaging and low resolution spectroscopy in Y, J and H bands, taking advantage of the high performance of the Large Binocular Telescope (LBT) AO systems. Its main scientific drivers is the detection and characterization of exoplanets, circumstellar disks, Solar System small bodies and acrive galactic nuclei. Binocular observations are provided by exploiting the synergy with SHARK-VIS (operating in V band) and LMIRCam of LBTI (operating from K to M band). SHARK-NIR was shipped to LBT in June 2022, and up to November 2022 was the subject of the three pre-commissioning runs: the first to install and test the instrument in the high-bay LBT clean tent, the second to install and align the instrument to the telescope and the third to perform daytime testing. This pre-commissioning phase resulted in the successful alignment of the instrument with a very good internal optical quality and the performance of additional tests using simulated turbulence injected through LBT Adaptive Secondary Mirror. In January 2023 we had the first commissioning run and the instrument first light, in which we successfully tested the imaging capabilities with and without the Gaussian Lyot coronagraph. In March 2023 we had the second commissioning run, in which despite the bad weather we successfully performed a variety of technical activities, as well as preliminary testing of the Shaped Pupil coronagraph. After two additional commissioning runs in May and October, our first early scientific run in October 2023 focused on the Taurus star formation region, a region populated by targets of considerable scientific interest. In this paper we will give an overview of commissioning and the early science phases running from October 2023 to May 2024, focusing on the technical challenges we overcame and future work needed to push the instrument to its very limit, as well as presenting the first preliminary scientific results.

The Keck Planet Imager and Characterizer (KPIC), a series of upgrades to the Keck II Adaptive Optics System and Instrument Suite, aims to demonstrate high-resolution spectroscopy of faint exoplanets that are spatially resolved from their host stars. In this paper, we measure KPIC’s sensitivity to companions as a function of separation (i.e., the contrast curve) using on-sky data collected over four years of operation. We show that KPIC is able to reach contrasts of 1.3 × 10⁻⁴ at 90 mas and 9.2 × 10⁻⁶ at 420 mas separation from the star, and that KPIC can reach planet-level sensitivities at angular separations within the inner working angle of coronagraphic instruments such as GPI and SPHERE. KPIC is also able to achieve more extreme contrasts than other medium-/high-resolution spectrographs that are not as optimized for high-contrast performance. We decompose the KPIC performance budget into individual noise terms and discuss limiting factors. The fringing that results from combining a high-contrast imaging system with a high-resolution spectrograph is identified as an important source of systematic noise. After mitigation and correction, KPIC is able to reach within a factor of 2 of the photon noise limit at separations < 200 mas. At large separations, KPIC is limited by the background noise performance of NIRSPEC.

FRIDA is a diffraction-limited imager and integral-field spectrograph for the adaptive-optics focus of the Gran Telescopio Canarias. In imaging mode FRIDA provides scales of 10, 20 and 40 mas/pixel and in IFS mode spectral resolutions of about 1200, 4000 and 30,000. Coronographic masks are available in both modes for highcontrast images. FRIDA is undergoing systems integration and is scheduled to complete system testing at the laboratory in December 2024 and to be delivered to the telescope shortly thereafter. In this contribution we present a summary of its design, fabrication, current status and potential scientific applications.

We describe the Sloan Digital Sky Survey Local Volume Mapper Instrument (LVM-I) construction, testing, and initial performance. The facility is designed to produce the first integral map of thousands of degrees of the Southern sky. The map will cover spectra from bluer than [O II] to 980 nm with a dispersion of over R = Δλ/λ > 4, 000 at Hα wavelength. Each spaxel will have a pitch of ∼35′′, and the survey will be conducted using four integral field units (IFUs) with an instantaneous field of view of 530 arcmin². The LVM facility is designed to achieve the required sub-Rayleigh spectroscopy over large sky areas with outstanding spectrophotometric accuracy and precision. LVM-I is designed to produce this unique dataset using four siderostats on commercial mounts. The four beams are fed into 16-cm-diameter f/11.4 apochromatic objectives, and the sky is derotated with K mirrors. These telescopes produce an image of the field onto both guider cameras and a lenslet array. The array reimages the field at f/3.7 onto 107-micron-diameter fibers. Blue throughput is maximized with a short 18.5-m fiber run from the IFUs to the spectrographs. The fibers are reconfigured inside a splicing box to distribute the fibers from the four telescopes to three spectrographs. The spectrographs are near-copies of the Dark Energy Survey three-band f/1.7 spectrographs, which deliver sharp images over the entire chromatic range. Nine STA charge-coupled devices (CCDs), cooled with liquid-nitrogen dewars, are used for the survey. The LVM-I is controlled with custom Python software and distributed over various computers using power-over-ethernet networking. The system is housed in a custom enclosure with a roll-off roof to grant access to the sky. The enclosure allows all four telescopes to point all over the sky and measure the transmissivity of the atmosphere and the sky background. Some of the first-light data products are highlighted here.

TARSIS (Tetra-Armed Super-Ifu Spectrograph) is a wide-field IFU with an 8-arcmin² FoV that has been already adopted by the Calar Alto Observatory (CAHA) for its 3.5m telescope and is currently under preliminary design phase. TARSIS makes use of image-slicers to cover its FoV than feed four spectrographs yielding a spectral resolution of R~1000 in the range between 320-520nm (three spectrographs/quadrants/arms) and 510-810nm (one spectrograph/quadrant/arms) with a spaxel size of ~2x2 arcsec². The scientific objective of TARSIS is to carry out the CATARSIS survey, a blind-spectroscopic mapping of 16 galaxy clusters in the range 0.15 < z < 0.23 up to their virial radii that will make use of all available dark time at the CAHA 3.5m for six years. CATARSIS will start as soon as TARSIS is available at the telescope, which is estimated for 2028.

Narrowband integral field spectrographs (NB-IFS)—capable of obtaining simultaneous, moderate to high-resolution spectra over a wide and continuous field of view, and within a constrained pass-band—represent a relatively new class of UV-visible astronomical instrumentation. With its exquisite low surface brightness sensitivity, the NB-IFS is optimal for velocity-resolved, emission-line mapping of a wide range of extended astrophysical phenomena. We have recently deployed CHaS, the Circumgalactic H-alpha Spectrograph on the MDM 2.4m Hiltner telescope on Kitt Peak, AZ, and are currently developing new NB-IFS concepts for ground- and space-based applications. We present here a generalized framework for designing, optimizing and assessing the optomechanical designs of NB-IFS over a broad range of scales, architectures, and capabilities. We also present a suite of novel architectures that highlight the differing ways that astrophotonics, metasurfaces, proposed detector technologies and image processing techniques will continue to advance NB-IFS capabilities over the coming decade.

BlueMUSE is a blue-optimised, medium spectral resolution, panoramic integral eld spectrograph under development for the Very Large Telescope (VLT). With an optimised transmission down to 350 nm, spectral resolution of R~3500 on average across the wavelength range, and a large FoV (1 arcmin²), BlueMUSE will open up a new range of galactic and extragalactic science cases facilitated by its specific capabilities. The BlueMUSE consortium includes 9 institutes located in 7 countries and is led by the Centre de Recherche Astrophysique de Lyon (CRAL). The BlueMUSE project development is currently in Phase A, with an expected rst light at the VLT in 2031. We introduce here the Top Level Requirements (TLRs) derived from the main science cases, and then present an overview of the BlueMUSE system and its subsystems ful lling these TLRs. We speci cally emphasize the tradeo s that are made and the key distinctions compared to the MUSE instrument, upon which the system architecture is built.

4MOST is a versatile spectroscopic facility soon to be installed on the ESO VISTA Telescope at Paranal. Prior to shipment to Chile, our team is conducting a comprehensive characterization of the instrument in a controlled laboratory setting. This preparatory phase is crucial for ensuring the fulfilment of both technical specifications and some key user requirements. The goal of this verification campaign is to obtain characterization data which will benchmark the performance of the spectrographs and the calibration unit against established metrics. The data primarily tests the spectral performance of the three spectrographs, the stability of the system, including the calibration unit, as well as the fiber throughput, which are pivotal for the success of 4MOST’s ambitious science goals. Additionally, the verification contains a selection of user requirements, ensuring the instrument’s readiness for the diverse scientific objectives it aims to enable. The results from these tests inform the observational strategy for future normal science operations. In this paper we outline the undertaken preparatory work, the applied testing procedures, and the anticipated implications of these tests, and their results, in the context of the final verification at the telescope, commissioning and normal science operations. This initial test phase marks a critical juncture in the 4MOST project timeline, setting the stage for a successful commissioning.

The Diffraction-Limited Near Infrared Spectropolarimeter (DL-NIRSP) is a facility instrument of the U.S. National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST). DL-NIRSP was originally commissioned with a birefringent fiber optic image slicer for high resolution observations of the solar atmosphere to support contiguous 2D-spatial, spectral, and polarimetric measurements in three channels between 500 and 1800 nm with very high spectral resolution over narrow bandpasses. During commissioning, we found temporal variations of the flat field and other fiber-related issues limited instrument performance. To resolve these various problems, we replaced the existing fiber-based image slicer with the high resolution Machined Image Slicer Integral Field Unit with 36 micrometer wide slicer mirrors (MISI-36). We report on the implementation and optical testing of MISI-36.

EMIR was shipped to the GTC on May 2016 and had its first light on June 2016. Since the beginning, the EMIR performances have been severely hampered by the many instabilities in the infrared detector, a 2048x2048 Hawaii2, built with the old original technology of the Teledyne Hawaii series. Despite of this, the instrument has proven to be powerful enough so as to produce a significant number of important scientific contributions. Starting in 2020, we initiated a new project aimed at equip EMIR with a most modern detector array, free from the artifacts that contaminated the observations with the old one. As a results EMIR has recently been upgraded with a new Hawaii2RG infrared detector which has superior performances virtually in every aspect compared with the old one. Not only the new detector is more sensitive, virtually in every aspect, compare with the old one but it also lacks the many instabilities of the original detected that have severely hampered the performances of EMIR, while it is not free from artifacts that increases the noise in the measurements. This is particularly noticeable under high illumination conditions, i.e. broad brand imaging, as it will be shown below. In addition, the new detector sits on a remotely operated gimbal mount that permits an exquisite alignment in the field of view. The detector is controlled by the SIDECAR integrated controller and a Markury Scientific MACIE interface card over IP communication.

GHOST is a newly operational optical fiber-fed high-resolution spectrograph at the Gemini South 8.1m telescope. It currently offers the choice of two resolution modes captured by one (or two) input IFUs with a FOV of 1.2” and a spectral resolving power of 56,000 and 76,000 for the unbinned CCDs. At the high-resolution mode, one can also instigate a simultaneous ThXe calibration lamp, which along with a simultaneous pseudo-slit profile constructed from reformatting the input IFU image will allow for precision radial velocity measurements. Here we talk about the proposed roadmap towards full queue operations, potential upgrades, and the error terms contributing to the final on-sky RV precision, which is estimated to be in the 1-10ms⁻¹ range.

We report the on-sky performance of two new integral field units (IFUs) for the Gemini Near-Infrared Spectrograph (GNIRS). The IFUs were designed and built at the Centre for Advanced Instrumentation in Durham University, as part of Gemini’s Instrument Upgrade Program. The Low Resolution IFU (LR-IFU) has a field-of-view of 3.15" ´ 4.80" sampled with a pixel scale of 0.15". It currently covers the X, J, H, and K nearinfrared bands with a spectral resolution of R~1700−7200 depending on the grating. Observations with the LRIFU can be combined with the “super-seeing” mode offered by Gemini-North (LGS+PWFS1), which can improve the sharpness of the PSF to below the Nyquist sampling. The High Resolution IFU (HR-IFU) has a 1.80" × 1.25" field-of-view at a 0.05" sampling, and is optimized for fully adaptively corrected images delivered by the Gemini North ALTAIR AO system. In addition, the GNIRS HR-IFU extends Gemini’s integral field capabilities in wavelength out to the thermal infrared, i.e., in the L and M bands, with 0.2” spatial resolution and up to a spectral resolution of R~18,000. Thanks to their exceptional throughput (70-85% of the long slit width matching the size of the slicer), the commissioning of these modes opens up new scientific opportunities for spatially resolved spectroscopy on Gemini, including study of the kinematics of stellar outflows around high-mass young stellar objects, probing the AGN-Starburst connection in active galactic nuclei, estimating black hole masses from infrared line diagnostics, resolving spectroscopy of gravitationally lensed galaxies and resolving jet dynamics in Herbig-Haro objects.

The InfraRed Doppler (IRD) instrument is the Subaru telescope’s high-resolution (R > 70,000) spectrograph covering wavelengths from 1000 to 1700 nm. A laser frequency comb (LFC) spectrum simultaneously obtained with an object spectrum calibrates wavelength shifts caused by instrumental instability. We originally developed IRD to carry out precision radial velocity (RV) measurements at near-infrared wavelengths. The wide wavelength coverage of IRD, and the large mirror (8.2 m) of the Subaru Telescope enables IRD to provide the best sensitivities to detect a planet orbiting a cool M-type star. The first science operation of IRD was conducted in 2018 and the large strategic blind survey for planets orbiting cool M-type stars started in 2019. Since then, there have been many observations not only for exoplanet category but also for stellar physics, Galaxy, and high-energy astrophysics. IRD spectroscopy allowed for characterizing exoplanet atmospheres by measuring OH emissions, He absorptions, and spin-orbit obliquities. The IRD survey discovered a super-Earth in orbit near a habitable zone of Ross 508. The IRD RV measurements for many systems that host transiting planets, including TOI-2285 b and Gliese 12 b, helped confirm those and determine or constrain their masses. Using REACH, IRD can be combined with the extreme adaptive optics SCExAO, enabling the use of a single-mode fiber and characterizations of faint sub-stellar companions orbiting bright stars. In this proceeding paper, we review and highlight the scientific results achieved by the IRD observations.

We assessed the impact of Earth’s atmospheric absorption lines, known as telluric contamination, on near-infrared radial velocity (RV) measurements using IRD/Subaru. We focused on the telluric removal process implemented in the RV pipeline for IRD data, which works in two phases: the creation of a stellar template spectrum and the measurement of RVs through a forward modeling approach. Our analysis revealed that discrepancies of approximately 1% exist between the observed telluric standard star’s spectra and theoretical telluric spectra, both used within the RV pipeline. These discrepancies are particularly significant in regions with strong water vapor absorption. Additionally, we investigated the impacts of residual tellurics on RV measurements through mock spectrum analysis. By comparing RV values derived from mock spectra made with either theoretical or observed tellurics, we found that residual tellurics can introduce an additional scatter of at least 1 m/s in RV measurements. Our findings highlight the necessity for improved telluric removal methods in the near-infrared spectrum to achieve precise RV measurements critical for detecting small-mass planets.

The Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory consists of a series of upgrades to the Keck II Adaptive Optics system and the NIRSPEC spectrograph to enable diffraction-limited, high-resolution (R∼35, 000) spectroscopy, originally in the K (∼2.0−2.5 μm) and L (∼3.2−3.7 μm) bands only. Phase I consisted of single-mode fiber injection/extraction units used in conjunction with an H band pyramid wavefront sensor. Using single-mode fibers provides a gain in stellar rejection, a substantial reduction in sky background, and a stable, well-defined line-spread function on the spectrograph. In 2022, Phase II brought a 1000-actuator deformable mirror, beam-shaping optics, a vortex fiber nulling mode, and more.

In this paper we present the results of the latest upgrades to the KPIC instrument. Among these upgrades, a second fiber bundle with related injection/extraction optics and new dichroics were added to extend KPIC’s science capabilities to y through H band, and to provide access to laser frequency combs for spectral calibration from y-K. Additionally, the charge 2 vortex mask for fiber nulling was supplemented with a charge 1 mask to enable spectroscopy of low mass companions at very small angular separations. Other upgrades included an atmospheric dispersion corrector, a new calibration source switching system, and an optimized tip/tilt control system. Here we show preliminary results of on-sky tests performed in the first few months of re-commissioning, along with the next steps for the instrument.

The Keck Planet Imager and Characterizer (KPIC) combines high contrast imaging with high resolution spectroscopy (R∼35,000 in K band) to study directly imaged exoplanets and brown dwarfs in unprecedented detail. KPIC aims to spectrally characterize substellar companions through measurements of planetary radial velocities, spins, and atmospheric composition. Currently, the dominant source of systematic noise for KPIC is fringing, or oscillations in the spectrum as a function of wavelength. The fringing signal can dominate residuals by up to 10% of the continuum for high S/N exposures, preventing accurate wavelength calibration, retrieval of atmospheric parameters, and detection of planets with flux ratios less than 1% of the host star. To combat contamination from fringing, we first identify its three unique sources and adopt a physically informed model of Fabry-Pérot cavities to apply to post-processed data. We find this strategy can effectively model the fringing in observations of bright stars, reducing the residual systematics caused by fringing by a factor of 2. Next, we wedge two of the transmissive optics internal to KPIC to eliminate two sources of fringing and confirm the third source as the entrance window to the spectrograph. Finally, we apply our previous model of the Fabry-Pérot cavity to new data taken with the wedged optics to reduce the amplitude of the residuals by a factor of 10.

LOFAR is currently the largest radio telescope operating at the lowest frequencies that can be observed from earth. It is a distributed telescope with a dense core of stations located in the north of the Netherlands combined with international stations across Europe, creating a telescope the size of Western Europe. LOFAR is currently being upgraded to LOFAR2.0. We present an overview of the validation of the new timing distribution system, showing the improvements in timing stability for the upgraded LOFAR2.0.

The world's largest low-frequency (10-250MHz) radio telescope, the pan-European Low-Frequency Array (LOFAR), is undergoing an upgrade of its hardware, firmware and software to improve its unique observing capabilities. The upgrade targets a variety of scientific use cases, ranging from galaxy evolution, transients and cosmic rays to space weather and lightning research. The LOFAR2.0 upgrade will increase the sensitivity of the telescope by doubling the number of digitized antennas operating in the 10-90 MHz frequency range, and allowing simultaneous observing with the antennas between 110 and 250 MHz. We present the validation of the LOFAR2.0 system following a stepwise approach, measuring its performance according to increasing complexity. Early integration test systems has ensured a smooth transition from validating a single receiver to the full-scale station. Subsequent array releases integrate the upgraded stations, combined with an upgraded clock distribution, network, central processor and telescope manager to validate the LOFAR2.0 telescope incrementally and ensure smooth transition to operations.

MOONS is the Multi-Object Optical and Near-infrared Spectrograph for the ESO Very Large Telescope (VLT). MOONS will be able to simultaneously observe ~1000 targets using individual robotic theta-phi positioners. The instrument will provide both medium and high-resolution spectral coverage across the wavelength range of 0.65 μm to 1.8 μm. In this paper we will describe the integration and testing of the fully-assembled Rotating Front End of MOONS. This incorporates the fibre positioning module, the front-end structure and the metrology, calibration and acquisition sub-systems. There will also be a discussion of system control and associated hazard analyses and safety cases. The as-built performance of the completed system will be demonstrated, including metrology-verified fibre positioning accuracy, reconfiguration efficiency, and flat-field fibre calibration performance. Finally, a summary of the successful installation of the field corrector assembly at VLT UT1 will be presented.

MOONS is a Multi-Object Optical and Near-infrared Spectrograph currently under testing as a third-generation instrument for the Very Large Telescope (VLT).The Infrared detectors used on MOONS are contained within a large, 4mx2.5mx2.5m cryostat with a 4 Tonne cold mass. Pumpdown of the chamber to 2x10-5mbar is achieved within 24 hours using two Pfeiffer 2000l/s turbo pumps. Initial Cooldown of the instrument uses a gravity fed LN2 Precool System with level sensors to automatically control the LN2 flow. When the cryostat reaches it’s assigned operating temperature an active cooling system takes over to maintain the steady-state temperature. Integration and engineering tests have been carried out to assess the performance of the Cryostat and Control System. This poster presents an overview of the system, results from integration and thermal testing of the system, along with unforeseen issues and how these challenges were resolved.

The predicted efficiency of the Prime Focus Spectrograph (PFS) for the Subaru telescope at Mauna Kea took a serious hit at the discovery of an error in the mounting of its volume phase holographic gratings (VPHG). Alerted by unexpected jumps in spectral flux between the blue and red channels in the first two spectrograph modules as they became available on sky, inspection of the gratings as mounted into the fourth and last module, still present in the lab, confirmed that all its gratings – three low-resolution (blue, red, NIR) gratings and a medium resolution grating and prism assembly (grism) – were indeed all mounted upside down. In this paper, after reporting on the observations leading to this discovery, we describe the corrective actions taken, illustrating by on-sky spectra full recovery of performance. Finally, we discuss the causes for this potentially catastrophic error, with an emphasis on the difficulty of ensuring verification at all levels (preliminary and final design, procurement, manufacturing, and AIT phases) for the giant instruments we are currently building and designing. We provide guidelines for future instrument designers in order to minimize the risk of such flaws happening again.

PFS (Prime Focus Spectrograph) is an ultra-wide-field, multi-object spectrograph currently being commissioned at Subaru telescope. The focal plane is made of ∼2400 science fibers and fiber positioners at the telescope prime focus, covering a field of view of 1.3 deg in diameter. The science fibers will be connected to 4 identical spectrograph modules, each receiving ∼600 fibers. Every spectrograph module will host 3 cameras, covering the blue (380–650 nm), red (630–970 nm) and near-infrared (940–1260 nm) wavelengths. This presentation will focus on the completion of the PFS spectrograph modules at the Subaru telescope. We will present their integration and test processes and measured performance, as well as the technical challenges encountered along the way, and the solutions used to correct them.

The Subaru Prime Focus Spectrograph (PFS) will soon be the first massively multiplexed wide-field spectrograph on an 8-meter class telescope. PFS’s spectrograph system covers the optical to near-infrared—380 to 1260 nm—in a single exposure and is fed by 2394 reconfigurable fibers distributed across a 1.3-degree wide field of view. Building upon deep multiband imaging catalogs, particularly from Subaru’s Hyper Suprime-Cam (HSC) imager, PFS will fuel future discoveries in cosmology, galaxy evolution, and galactic archaeology. To fully leverage Subaru’s 8.2 meter aperture and probe the faintest targets, accurate spectral reduction and sky subtraction are critical to PFS’s operation. During commissioning of PFS, the accuracy of the sky-subtraction algorithms is being assessed through direct observations of the night sky. In this paper, we report the current status of the sky-subtraction routines, as determined from the commissioning data.

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS covers 1.3-degree diameter field with 2386 fibers to complement the imaging capability of Hyper Suprime Cam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners with science fibers are located. The PFI was delivered to the Subaru telescope in June 2021. Consequently, several tests and engineering runs were carried out to calibrate the PFI and also verify the performance of the PFI with the telescope. Some improvements were made including the focus adjustment of the acquisition and guiding cameras to match which of the science fibers, and the calibration of the AG camera positions and the flux calibrations. The key performance for PFI is so called the convergence rate, i.e. the successful rate of the Cobra positioners to reach the target positions within the assigned time. The convergence process includes iterations between movements of Cobra positioners and imaging of the metrology camera system for measuring the fiber positions. Through commissioning runs, we accumulated enough data to analyze the possible factors that affect the convergence rate such as the calibration accuracy for the distortion of the wide field correctors, the thresholds to stop the positioner movement, the exposure time for the metrology camera and the dome seeing, etc... With these efforts, several improvements have been implemented to enhance the performance of the positioners and determine the optimal iteration number. The overall convergence time has also been reduced substantially. We will report the analysis and improvement done in this paper.

We present the results of optical performance verification for the Prime Focus Spectrograph (PFS) fiber optics module, so-called “CableBs”, at Subaru Telescope. PFS is the next generation ultra-wide field multi object spectrograph. It employs 2386 fibers of which the fiber tips are placed precisely on the primary focal plane over a field of view of 1.3 degrees in diameter. CableB transfers light from the fiber positioning module, or Prime Focus Instrument, to the spectrographs. PFS utilizes four CableBs and each of them carries just over 600 science grade fibers. We completed installation of all CableBs at the telescope in June 2023 after two-years of intermittent work. The optical performance of each CableB was subsequently assessed, focusing on four areas; continuity, uniformity, throughput, and focal ratio degradation (FRD). For examining continuity, we illuminated one termination of CableB with flat LED panel and observed the transmitted light. We found only one fiber newly broken during shipment from the integration site. We also checked uniformity of the relative intensity of light propagating in each fiber. The whole variations around the average intensities fit in 20% range among fibers in each CableB, which was consistent with the measurement before shipping. Throughput of sampled fibers were measured in a wavelength range from 400 to 1400 nm with commercial spectrometers. The measurement at the telescope and the integration site each showed a throughput of approximately 70%, so both sets of measurements are consistent. Finally, we measured FRD employing the collimated beam method to ensure that CableBs were free from any significant physical stress after the installation. Our FRD measurements were comparable before and after the installation. In addition, a long-term monitoring of over a few months showed FRD remained sufficiently stable for science operations. According to these results, we conclude that the installation of CableBs at Subaru Telescope was successful.

The Spectrograph System (SpS) of Subaru Prime Focus Spectrograph is fed by 2400 fibers and consists of four identical spectrograph modules with 4 arms and 600 fibers each. This paper outlines the overall integration process for the spectrograph module series as completed at the Subaru Telescope. Many partners from the Subaru PFS Collaboration and industry contributed to this large multi-object spectrograph system. The initial integration of the so-called "one-channel prototype" began in 2015. The first spectrograph module was delivered to Subaru in 2019, and the fourth module was delivered in late 2023, with delays due to both technical difficulties and scheduling challenges, including the impact of COVID-19 on the large PFS spectrograph system collaboration. The integration and validation of each spectrograph module were performed at the Laboratoire d’Astrophysique de Marseille (LAM) prior to delivery and full integration at the Subaru Telescope. First, we briefly review the opto-mechanical design and development strategy for the SpS. We present the integration and testing procedures developed for this mini-series of four spectrograph modules. Several specific AIT tools were innovative and key to the process, and are worth reporting, including the software tools required for functional tests, housekeeping, and environment monitoring during integration, analysis of dimensional metrology, test and verification of optical alignment, and overall performance assessment. Specific processes were also developed for analyzing and resolving anomalies and issues encountered. We detail the strategies developed to resolve technical issues: thermal and vacuum performance; dimensional and optical metrology processes to correct for focus/tilt anomalies observed at the focal plane; handling, alignment, and optical testing of large optics such as the 340x340x20mm Volume Phase Holographic Grating (VPHG). We briefly report on a grating orientation issue discovered before the delivery of the last module, which is reported elsewhere. We quickly report the integration logistics: managing the shipping process, custom, and deliveries of many parts and modules among partners since 2014, and the final delivery and installation at the Subaru Telescope at the summit of Mauna Kea in Hawai`i in 2019, 2022, and 2023. We then dedicate a full section to the optical and thermal performance for the largest 8m-class multi-object spectrograph: the spectral channels and camera alignment performance results and the detailed optical performance of the four spectrograph modules (extracted from internal extended performance reports).

The Robert Stobie Spectrograph (RSS) is an imaging spectrograph designed to occupy the Prime Focus Instrument Package of the Southern African Large Telescope (SALT). Grating spectropolarimetry, 3200 - 9000 ˚A, with resolution R up to 10 000, is always available, using rotating half and quarter waveplates near the telescope focal plane and a calcite mosaic beamsplitter in the collimated space. This paper describes improvements made to the polarimetric calibration to correct for an unexpected time-dependent position angle ‘ripple’ vs wavelength which has been seen in high-precision RSS observations, and which appears to be due to variations in illumination of the pupil during an observation. A new calibration technique, which explicitly models the pupil dependence of the polarimetric sensitivity, has been developed. The net spectral polarization sensitivity vs field of view position X, Y , and wavelength λ is computed as the polarization pupil dependence, weighted by the pupil intensity illumination of the observation. We find that the polarization pupil dependence, degree P and position angle θ are adequately represented by a polynomial function of position in the pupil. A pupil intensity illumination model for SALT has been devised, calibrated by twilight observations through a pinhole slitmask grid, observed out of focus. The polarization pupil dependence model has been calibrated using observations of the full Moon through a similar mask, plus a polaroid. The final calibration has been checked using repeated observations of known highly polarized standard stars.

Three fibre feed integral field units (IFUs), called Slit Mask IFUs (SMI), are being developed in the SAAO fibre-lab for the Robert Stobie Spectrograph (RSS). The smaller, 200 micron fibre IFU (SMI-200) has 309 x 0.9 arcsec diameter spatial elements covering an elongated hexagonal footprint of 18 × 23 arcsec is now being commissioned. The larger, 300 (400) micron fibre IFU, SMI-300 (SMI-400), has 221 × 1.35 arcsec (178 × 1.8 arcsec) diameter spatial elements covering an on-sky area of 18 × 29 sq. arcsec (21 × 44 sq. arcsec). In all SMI units there are two groups of 13 fibres offset by roughly 50 arcsec on either side of the primary array to sample sky. SMI-200 provides a median spectral resolution of 2400 at Hα wavelengths in a low resolution mode simultaneously covering 370 to 740 nm. At a higher grating angles the SMI-200 delivers spectral resolution up to 10,000. A future red spectrograph arm for RSS will extend the simultaneous wavelength coverage up to 900 nm at a median resolution of 6000 for the same IFU. With this upcoming red arm and with the fibre-fed, near-infared spectrograph NIRWALS on SALT, SMI-300 enables wavelength coverage from blue to NIR wavelengths at the same spatial resolution and footprint. The SMI units are inserted in the same fashion as the existing long-slit cassettes at the SALT focal plane. Prismatic fold mirrors direct the focal plane into the fibre IFU and then back into the RSS collimator after the fibres are routed 180 deg within the cassette and formatted into a pseudo-slit. Fold-prisms ensure that the spectrograph collimator continues to see the same focal plane. In this paper we report the laboratory characterization and on-sky commissioning-performance of the first Slit Mask IFU, SMI-200.

This paper presents the opto-mechanical integration and alignment, functional and optical performance verification of the NIR arm of Son Of X-Shooter (SOXS) instrument. SOXS will be a single object spectroscopic facility for the ESO-NTT 3.6-m telescope, made by two arms high efficiency spectrographs, able to cover the spectral range 350-2050 nm with a mean resolving power R≈4500. In particular the NIR arm is a cryogenic echelle cross-dispersed spectrograph spanning the 780-2050 nm range. We describe the integration and alignment method performed to assemble the different opto-mechanical elements and their installation on the NIR vacuum vessel, which mostly relies on mechanical characterization. The tests done to assess the image quality, linear dispersion and orders trace in laboratory conditions are summarized. The full optical performance verification, namely echellogram format, image quality and resulting spectral resolving power in the whole NIR arm (optical path and science detector) is detailed. Such verification is one of the most relevant prerequisites for the subsequent full instrument assembly and provisional acceptance in Europe milestone, foreseen in 2024.

The SOXS spectrograph, designed for the ESO NTT telescope, operates in both the optical (UV-VIS: 350-850 nm) and NIR (800-2000 nm) bands. This article provides an overview of the final tests conducted on the UV-VIS camera system using a telescope simulator. It details the system’s performance evaluation, including key metrics such as gain, readout noise, and linearity, and highlights the advancements made in the upgraded acquisition system. The testing process, conducted in the Padua laboratory, involved comprehensive simulations of the telescope environment to ensure the results closely resemble those expected at the ESO-NTT telescope. The successful completion of these tests confirms the system’s readiness for deployment to Chile, where it will be installed on the NTT telescope, marking a significant milestone in the SOXS project.

The Son Of X-Shooter (SOXS) is a single object spectrograph, built by an international consortium for the 3.58-m ESO New Technology Telescope at the La Silla Observatory. It offers a simultaneous spectral coverage over 350-2000 nm, with two separate spectrographs. In this paper we present the status of the Near InfraRed (NIR) cryogenic echelle cross-dispersed spectrograph, in the range 0.80-2.00 μm with 15 orders, equipped with an 2k x 2k Hawaii H2RG IR array from Teledyne, working at 40K, that is currently assembled and tested on the SOXS instrument, in the premises of INAF in Padova. We describe the different tests and results of the cryo, vacuum, opto-mechanics and detector subsystems that finally will be part of the PAE by ESO.

SOXS (Son Of X-Shooter) is the new single object spectrograph for the ESO New Technology Telescope (NTT) at the La Silla Observatory, able to cover simultaneously both the UV-VIS and NIR bands (350-2000 nm). The instrument is currently in the integration and test phase, approaching the Preliminary Acceptance in Europe (PAE) before shipment to Chile for commissioning. After the assembly and preliminary test of the control electronics at INAF - Astronomical Observatory of Capodimonte (Napoli), the two main control cabinets of SOXS are now hosted in Padova, connected to the real hardware. This contribution describes the final electronic cabinets layout, the control strategy and the different integration phases, waiting for the Preliminary Acceptance in Europe and the installation of the instrument in Chile.

SPIRou (SpectroPolarimètre Infra-Rouge in French), is a near-infrared, fiber-fed spectropolarimeter at the Canada-France- Hawaii Telescope (CFHT) which gives full spectral coverage from 0.98 to 2.35 μm with a resolving power of 70,000. To obtain an RV precision of ~1 m/s, SPIRou must measure and average the redshift of as many spectral lines as possible. The K-band contains many such lines making K-band sensitivity very important. Unfortunately, the original thermal background suppression design did not work as expected so that the background is over 5 times higher than desired reducing the K-band sensitivity by 2-3 magnitudes. Some of the background has been eliminated by cooling the fiber interface at the entrance to the spectrograph, but the fiber injection unit on the telescope still produces a large amount of background and is more difficult to cool. This paper will describe the cooling system installed on the SPIRou Cassegrain unit (fiber injection unit) and its performance.

The Transneptunian Automated Occultation Survey (TAOS II) is a three robotic telescope project to detect stellar occultation events generated by TNOs. TAOS II aims to monitor about 10000 stars simultaneously at 20Hz to generate a significant event rate. The TAOS II cameras are designed to cover the 1.7 degree diameter field of view of the 1.3m telescopes with a mosaic of ten 4.5k × 2k e2v CIS 113 CMOS sensors. The CIS 113 has a back-illuminated thinned structure to provide similar performance to that of back-thinned CCDs. The CIS 113 device has 16 micron pixels with 8 outputs, with a plate scale about 0.63”/pixel. With the freedom of direct row and column addressing, star boxes with sizes of 8 × 8 pixels in each sensor can be sampled at 20 Hz or higher with a pixel rate of 1M pixel/sec per channel. The sensors, mounted on a single Invar plate, are cooled to an operating temperature of about 200K by a cryogenic cooler. The gap between two sensors is about 0.5mm. The control electronics consist of an analog part and a Xilinx FPGA based digital circuit. One FPGA is needed to control and process the signal from each CIS 113 chip. Two large PCBs were used to fanout signals from the 10 CMOS devices through the vacuum chamber wall. A synchronization circuit receives a pulse from the control building to ensure the timing error of exposures of the three cameras is within 1 ms. The cameras were delivered and installed on the TAOS telescopes in 2023 and series of tests and adjustments have been carried out to optimize the performance. In this presentation, the camera performance in the full frame mode and the window mode will be detailed. The synchronization and the adjustment among the three cameras will also be presented.

We present upgrades to the visible-light (600nm to 800 nm) high-contrast imaging polarimeter, VAMPIRES, installed on the Subaru Coronagraphic Extreme Adaptive Optics instrument (SCExAO). These upgrades included low read noise, high dynamic range qCMOS detectors, a novel dichroic-based multiband imaging optic for spectral differential imaging, a suite of classic Lyot coronagraphs, and an achromatic fast polarization modulator. VAMPIRES is capable of diffraction-limited imaging (17 mas to 22 mas angular resolution) and achieves Strehl ratios up to ∼60% with 5σ coronagraphic contrast of 10^-4 at 0.1′′ and 10^-6 at >0.4′′. We highlight commissioning results from HD 169142, R Aqr, Neptune, and HD 1160B.

The Visible Aperture Masking Polarimetric Imager for Resolved Exoplanetary Structures (VAMPIRES) is a visible light instrument on the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. In a previous work, the instrumental polarization (IP) and crosstalk of VAMPIRES was characterized from measurements with a polarized internal calibration source. In this work, we use unpolarized standard star observations to estimate the polarization of Subaru’s Nasmyth mirror (M3) and use polarized standard star observations to quantify the overall system Mueller matrix model’s accuracy. We present an instrument matrix inversion routine that has returned stable results for all tested on-sky sources. With the current 675nm Mueller matrix model of VAMPIRES, the median residuals when retrieving the on-sky degree of linear polarization (DoLP) and angle of linear polarization (AoLP) of three polarized standards were 0.27% and 3.57% respectively.

WINERED is a PI-type near-infrared (z, Y, J-bands) high dispersion spectrograph developed by Koyama Astronomical Observatory of Kyoto Sangyo University and the University of Tokyo (Ikeda et al. 2022). In 2022, WINERED was moved to the 6.5-m Magellan II - Clay telescope at Las Campanas Observatory (LCO) to take advantage of its extremely high sensitivity (the instrumental total throughput ~60%), which is its best feature, and started scientific observations in 2023. This paper presents the details of the development undertaken for the relocation, the instrumental performance when attached to the Magellan telescope, and its operational structure and strategy. For the relocation to LCO, a new instrument transport cart was manufactured. This allows for installation on the Nasmyth platform within 30 minutes, without the need of special alignment tasks, and with highly reproducible accuracy. Since the 125mm back-focal length of the Magellan telescope was too short for WINERED, a new focal extender was fabricated and introduced to ensure proper focus on the slit. In addition, an original guider system was constructed by combining the Auto-Guider function of the Magellan telescope and WINERED's pre-existing slit viewer, and it was confirmed that a tracking accuracy of about 0.1 arcsec was achieved. This new guider system, which provides a function such as automatic dithering, has been highly regarded by observers, especially for remote observations which have become increasingly essential since the Covid-19 pandemic. Up to this point, utilizing WINERED on Magellan telescope, we have been able to obtain spectra with an SNR=30 (R=28,000) for a point source as faint as J=16 mag with just 1-hour of exposure even under a natural seeing condition. This sensitivity exceeds that of infrared high dispersion spectrographs on a 10-m class telescope, even though these spectrographs are usually utilized with AO. Currently, WINERED is operated under the collaboration of the Carnegie Observatories and LCO with the WINERED team responsible for the setup of the instrument, observing support in night time, and initial data reduction including the provision of data-reduction pipeline. As compensation, 20% of the total observation time, equating to 6 nights in the achievement of 2023, has been allocated to the WINERED team.

The Dutch Rubin Enhanced Atmospheric Monitor – DREAM – brings high-resolution, real-time information on all-sky transparency and cloud coverage to the Vera C. Rubin Observatory. Leveraging the MASCARA legacy, DREAM employs five wide-field cameras, pointing upward and in the four cardinal directions. It precisely measures the brightness of all bright stars (V < 8.4) with a cadence of 6.4 seconds. To disentangle instrumental and stellar brightness variations from transmission fluctuations, a comprehensive spatial-temporal calibration is applied. The resulting transmission variations are calibrated and processed to generate an all-sky image of transparency, providing the actual cloud cover at an approximate cadence of 30 seconds. DREAM also produces calibrated light curves for stars brighter than magnitude 8.4, extending the temporal coverage of the MASCARA southern hemisphere survey. Integrated and tested at Leiden Observatory in 2023, DREAM was shipped in November of the same year and installed in close proximity to the Vera C. Rubin Observatory. In its initial phase, DREAM supplies cloud coverage and transparency data to the Auxiliary Telescope. Once the LSST Camera of the Vera C. Rubin Observatory becomes operational, DREAM will play a crucial role in optimizing the survey strategy by providing input to the scheduler, particularly in non-photometric conditions.

The QUIJOTE (Q-U-I JOint TEnerife) experiment combines the operation of two radio-telescopes and three instruments working in the microwave bands from 10 to 47 GHz at the Teide Observatory, Tenerife, which has already been presented in previous SPIE meetings. The new Multi Frequency Instrument (MFI2) led by the Instituto de Astrofísica de Canarias (IAC) aims to characterize the polarized emission of the Cosmic Microwave Background (CMB), as well as Galactic and extra-Galactic sources, at medium and large angular scales. This instrument has five polarimeters, three working in the microwave band of 10-15 GHz, and two working in the microwave band of 15-20 GHz. The instrument is composed of a cylindrical aluminum 6061-T6 cryostat cooled by a closed Gifford-McMahon helium cycle cryocooler with two stage shields (first stage at 30 K, and second stage at 10 K). The opto-mechanical system consists of five horns aligned with the focal plane of the telescope where the signal enters the instrument, each horn is followed by an OMT, a 90º Hybrid and two LNAs cooled down below 20 K, all of which represents the Front-End Module (FEM). This signal leaves the instrument by a feedthrough where the Back End Module (BEM) waits at room temperature to process the signals.

MORISOT (MOnet Robotic Instrument for Spectroscopy Of Transients) is a low-resolution optical spectrograph installed at our 1.2 m robotic telescope MONET/South located at SAAO. The installation of the newly designed frontend at the telescope enabled the commissioning of MORISOT in December 2023. With this frontend, MORISOT will be able to run fully robotically by using the main camera of the telescope for simultaneous guiding. Moreover, a second 25-cm-telescope, mounted at MONET/South, can be used to simultaneously perform photometric observations of the spectroscopically observed objects. The fully robotic operations will be handled by our observatory control system pyobs, which already runs our robotic telescopes for photometric observations and will be extended to handle all the operations (guiding, spectroscopy and photometry) at once. First use cases will be a high-cadence survey of changing-look AGN and a survey of transiting exoplanets.

OPASpec is a double spectrograph covering the 360-880 nm range with a spectral resolution of R ~3000 on a single CMOS detector array. The blue channel (360-565 nm) and red channel (565-880 nm) combined cover this broad optical bandpass tailored to our observational goals for the Original PolyOculus Array (OPA). A dichroic splits incident light so that blue/red light are reflected/transmitted to the respective channel’s optical path. Each channel contains two separate collimating lenses, VPH transmission gratings, and a camera composed of custom lenses fabricated by Optimax. The two channels share the same detector plane — an Atik APX60 CMOS array. We present the design, fabrication, calibration, and first light of the instrument.

Polarimetric observations can provide important information on many astrophysical phenomena beyond that available via conventional imaging and spectroscopy alone. As a first step toward providing Gemini North instrument support for polarimetric observations, an instrument upgrade program is currently under way to bring one of the GPOL polarization modulator units (GPOL-N) into operation in concert with NIRI at Gemini North (GN) to provide an IR imaging polarimetry in the visiting instrument mode. Featuring three deployable trays that accommodate swappable, rotatable polarizing waveplates and calibration polarizers, GPOL is designed to facilitate polarimetric observations over the opticalinfrared wavelength range of 0.3 – 5 μm. When installed on the telescope, GPOL is physically situated inside the Acquisition and Guidance (A&G) unit, and is designed to work in concert with bottom port instruments containing an oninstrument Wollaston prism, such as NIRI. We present here an overview of the functional characteristics of GPOL and the current status of the GPOL+NIRI commissioning project. Following control board and software updates, the GPOL-N unit is currently undergoing further testing as a prelude to refurbishment. We also briefly discuss subsequent Gemini North polarimetric instrumentation plans, which include the possible future commissioning of a visitor mode that combines GPOL with the GNIRS multifunction spectrograph to provide NIR spectropolarimetry, and polarimetric imaging via the GPI 2.0 instrument.

In 2025, the Near-Infrared Camera 2 (NIRC2) at the 10-meter Keck II telescope will undergo an upgrade that will enable a suite of new polarimetric observing modes. This includes coronagraphic imaging, standard imaging, and spectropolarimetry in observing bands J through L′. The new modes will open up a wide range of studies such as investigations of exoplanets, the Galactic center, active galactic nuclei, and measurements of the solar system. The upgrade includes a Wollaston prism that was installed in NIRC2 in 2019 and a pair of half-wave plates (one for JHK bands and one for L′ band) to be installed in February 2025. The functionality of these waveplates must be evaluated before installation by characterizing their transmission and retardance. In this paper, we present results from characterizing the L′ band half-wave plate over the 1.1 to 1.95 μm range using a dual-rotating retarder polarimeter. In addition, we tested an anti-reflective nano-texture treatment that can be applied to the quartz JHK band waveplate in production. This treatment was found to improve transmission without significantly altering the retardance of a waveplate.

We report on two critical upgrades to NIRC2, the workhorse diffraction-limited infrared instrument in use with the Keck II telescope Adaptive Optics (AO) system at the W. M. Keck Observatory. NIRC2 has been in operation for over two decades and it is one of the most productive instruments at WMKO. The NIRC2 detector is a 1Kx1K InSb Aladdin-3. We have upgraded the detector electronics from the original system based on transputers to a state-of-the-art Archon controller. One of the most demanded NIRC2 observing modes is high-contrast imaging using Vector Vortex Coronagraphic (VVC) masks, which have been available to the NIRC2 observing community since 2015. To maximize the attenuation of the AO-generated Point Spread Function (PSF) core, the star needs to be precisely centered on the vortex mask over the course of an observation. This is achieved with a servo loop control software based on the Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing (QACITS) technique. We have migrated the original IDL-based QACITS software to Python, including several updates and a new graphical interface. Both Archon and QACITS upgrades are aimed at boosting the NIRC2 observing efficiency.

The Submillimeter Array (SMA) is an array of 8 antennas operating at millimeter and submillimeter wavelengths on Maunakea, Hawaii, operated by the Smithsonian Astrophysical Observatory and Academia Sinica Institute of Astronomy and Astrophysics, Taiwan. Over the past several years, we have been preparing a major upgrade to the SMA that will replace the aging original receiver cryostats and receiver cartridges with all new cryostats and new 230 and 345 GHz receiver designs. This wideband upgrade (wSMA) will also include significantly increased instantaneous bandwidth, improved sensitivity, and greater capabilities for dual frequency observations. In this paper, we will describe the wSMA receiver upgrade and status, as well as the future upgrades that will be enabled by the deployment of the wSMA receivers.

RoboPol is a four-channel, one-shot linear optical polarimeter that has been successfully operating since 2013 on the 1.3 m telescope at Skinakas Observatory in Crete, Greece. Using its unique optical system, it measures the linear Stokes parameters q and u in a single exposure with high polarimetric accuracy of 0.1%-0.15% and 1 degree in polarization angle in the R broadband filter. Its performance marginally degrades in other broadband filters. The source of the current instrumental performance limit has been identified as unaccounted and variable instrumental polarization, most likely originating from factors such as temperature and gravity-induced instrument flexure. To improve the performance of RoboPol in all broadband filters, including R, we have developed a rotating half-wave plate calibrator system. This calibrator system is placed at the beginning of the instrument and enables modulation of polarimetric measurements by beam swapping between all four channels of RoboPol. Using the new calibrator system, we observed multiple polarimetric standard stars over two annual observing seasons with RoboPol. This has enabled us to achieve a polarimetric accuracy of better than 0.05 % in both q and u, and 0.5 degrees in polarization angle across all filters, enhancing the instrument’s performance by a factor of two to three.

The new VLBI data acquisition system (OCTAVE-DAS) have been developed for VLBI Exploration of Radio Astrometry (VERA) and the East Asia VLBI Network (EAVN) based on the VSI-H and VDIF specifications at the National Astronomical Observatory of Japan. It consists of 1) a high speed 1-20 Gsps 3-10 bit RF(-30 GHz) direct sampler with DBBC functions, 2) media converter between one 10 GigE port and four 2 Gbps input and output ports conformable to VSI-H, 3) new VLBI recorders have functions of both recording and playing at a maximum rate of 32 Gbps and 4) Gbit real-time correlator and software correlator system using GPGPU technology. These OCTAVE-DAS instruments are connected via 10 GigE network with VDIF and VSI specifications. These components have been used for VERA, Japanese VLBI Network (JVN) and EAVN. We will report on current status and results of scientific broad-band (16 Gbps) VLBI test observation using the OCTAVE-DAS.

DDRAGO is the first light instrument for the 1.3-m COLIBRÍ robotic telescope at the Observatorio Astronómico Nacional, San Pedro Mártir, Baja California, México (OAN-SPM). COLIBRI was developed by France and Mexico in support of the Sino-French SVOM satellite with its ECLAIRs instrument, designed to provide initial follow-up of GRBs. DDRAGO will also support a much wider program of observations of transient and multi-messenger sources. It is a wide-field multi-channel imager consisting of two parts: DDRAGO and CAGIRE. DDRAGO has blue and red channels, and it also delivers an infrared beam to the CAGIRE imager which will be installed soon after. Here we briefly recall the design and discuss the prototyping, fabrication, integration, and verification of DDRAGO. The installation and commissioning of the instrument at the OAN will start shortly.

The programmable Liquid-crystal Active Coronagraphic Imager for the DAG Telescope (PLACID) instrument will be installed on the Turkish 4-m Telescope by the fall of 2024 and is expected to be on-sky by the end of the year. PLACID will be the first “active stellar coronagraph instrument”, equipped with a customized spatial light modulator (SLM), which performs as a dynamically programmable focal-plane phase mask (FPM) from H- to Ks- band. A Python-based numerical simulator of SLM-based focal-plane phase coronagraph is developed to investigate the effects of discrete pixelated FPM patterns in place of classical phase masks. The simulator currently explores the impacts of two design choices, spatial sampling in the coronagraphic focal-plane (number of SLM pixels per λ/D) and phase resolution (SLM greylevel steps). The preliminary results of the monochromatic simulations show that in ideal conditions (no wavefront errors) it is sufficient to use FPMs with spatial sampling of 10 SLM pixel per λ/D and phase resolution of 8 bits. The tool is expected to enable detailed simulations of PLACID or similar SLM-based instruments, and to help with real-time operations (optimal choice of FPM for given observing conditions) and interpretation of real data. Additionally, the tool is designed to integrate and simulate advanced operation modes, in particular focal-plane phase diversity for coherent differential imaging (CDI) of exoplanets.

The world’s first ever “adaptive stellar coronagraph” facility will be the PLACID instrument, installed on Turkey’s new national observatory 4-m DAG telescope. PLACID incorporates a customized spatial light modulator (SLM) acting as a dynamically addressed focal-plane phase mask (FPM) coronagraph in the H – Ks bands. This new approach to high-contrast imaging will be applied on-sky in late 2024/early 2025. We present a first estimate of the science discovery space for PLACID, in terms of known exoplanets and brown dwarfs, considering raw lab contrast, contrast ratios, limiting magnitudes, coronagraphic inner working angle etc. In the future, we will also look into predicted disk and binary or multiple stars systems imaging performance, with the latter being a possible niche science case for the instrument (adaptive FPM for multiple stars). This work will inform on the first light PLACID commissioning activities and early science on the DAG telescope and is deemed to evolve in function of future developments on the DAG AO instrumentation suite.

We are developing an imager with high throughput in near-ultraviolet wavelengths (300-400 nm) for a ground-based telescope. The transmittance in this wavelength range has been given the highest priority by optimizing the optical design and detector selection. Including the atmosphere and telescope optics, we expect the peak efficiency of the imager as around 32 percent in the u-band from model calculations. The expected limiting magnitude with a signal-to-noise ratio of five is about 20.2 AB magnitudes for 100 seconds of exposure in the u-band. This allows us to detect NUV emission from nearby transient objects, for example, a kilonova from a neutron star merger closer than 130 Mpc within a day after its collapse. In March 2024, we conducted the first on-sky observations of the imager at the 1.5-m Kanata Telescope at Higashi-Hiroshima Observatory. Some of the instrument specifications have been confirmed to be as designed through preliminary analyses.

Las Cumbres Observatory (LCOGT) operates a global network of robotic 0.4, 1.0, and 2.0-meter telescopes to facilitate scientific research and education in time-domain astronomy. LCOGT’s flagship educational program, Global Sky Partners (GSP), awards up to 1500 hours per year of telescope time to individuals and organizations that run their own, fully supported, educational programs. The GSP has a presence in 40 countries and 45% of the Partners target under-served, under-represented, and developing world audiences. The degradation and obsolescence of the original 0.4-meter telescope network prompted LCOGT to update the fleet of 10 telescopes to a new system consisting of predominantly off-the-shelf products. New PlaneWave DeltaRho 350 telescopes with Gemini Focuser/Rotators, LCOGT filter wheels, and QHY600 CMOS cameras, complement the original, custom-built mount. The deployment of all ten telescopes was completed in March 2024. We describe the design and performance of this new system and its components. We comment on modifications made to the QHY600 cameras, as well as on the treatment of random telegraph noise of its CMOS detectors within our data processing system BANZAI. The new telescope network supports the GSP program as well as multiple key science projects, including follow-up observations for the TESS satellite mission.

We have developed a simultaneous near-infrared camera, kSIRIUS, for the Kagoshima University 1m telescope. This camera has three focal planes created by two dichroic beam splitters for the J (λ = 1.21μm), H (λ= 1.65μm), and Ks (λ = 2.15μm) bands. kSIRIUS is designed to have three ∼ 10′ × 10′ fields of view with a seeing-limited resolution (∼ 1.5′′ at Kagoshima University Iriki Observatory) all over the fields. However, we have not yet obtained large format array detectors, so three small InGaAs array detectors are placed at the three focal planes. These detectors, which have 320×256 pixels, are newly manufactured for astronomy at Hamamatsu Photonics K. K., Japan, in collaboration with us, and cover three 3.7′ × 2.9′ fields of view with a pixel scale of 0.69′′. These three detectors enable a simultaneous imaging observation of the J, H, and Ks bands. We performed a test observation of kSIRIUS on the 1m telescope in January 2023. The stellar image quality is reasonably good compared to the typical site seeing. We have also determined the limiting magnitudes as J: 16.3, H: 15.3, and Ks: 14.5 (270 sec integration, S/N = 10, Vega magnitude), which are consistent with the expected values. We also have an optical g′ and i′ band camera covering 10′×10′ fields of view, working together with kSIRIUS. This setup allows us to acquire five (g′i′JHKs) images simultaneously, and will be particularly useful for studying any kind of time variable targets.

The Wide-Field Infrared Transient Explorer (WINTER) is a new near-infrared time-domain survey instrument installed on a dedicated 1-meter robotic telescope at Palomar Observatory in June of 2023. WINTER’s science goals include robotic follow-up of kilonovae from binary neutron star (BNS) and neutron-star black-hole (NSBH) mergers, surveys to study galactic and extragalactic transients and variables, along with building up a deep, coadded image of the near-infrared sky. The project also serves as a technology demonstration for new large-format Indium Gallium Arsenide (InGaAs) detectors for cost-effective near-infrared photometry without cryogenic cooling. WINTER’s custom camera combines six InGaAs detectors as a first run of a newly-designed 1920 x 1080 pixel read out integrated circuit (ROIC). It uses a novel tiled fly’s-eye optical design to cover a > 1 degree-squared field of view in Y-, J-, and shortened-H-band filters (0.9-1.7μm). The survey currently operates with a median limiting magnitude of J_AB ≈ 18.5, running nightly robotic surveys and target of opportunity programs. In parallel to these science programs, there is ongoing work to improve WINTER’s performance, which shows a factor of ∼ 10 decreased instrument efficiency from the design. Laboratory and on-sky testing suggest the sensor’s InGaAs diode array is performing properly, but sensitivity is being lost during amplification in the ROIC’s pixel amplifier. We present the laboratory and on-sky performance newly-commissioned WINTER observatory along with ongoing and future efforts to improve performance.

Optical SETI (Search for Extraterrestrial Intelligence) instruments exploring the very fast time domain, with large effective collecting areas and large sky coverages, are particularly well-suited for the detection of optical techno-signatures and astrophysical transient sources. The Panoramic SETI experiment (PANOSETI) aims to observe optical transients from nanosecond to second precision across a wide instantaneous field-of-view (~100 sq.deg. per telescope pair) by using two or more assemblies of telescopes to reject spurious signals by coincidence detection. On-sky results from pairs of PANOSETI telescopes deployed at Lick Observatory using baselines <700m are presented to evaluate instrument performance and false alarm rates.

Cryoscope Pathfinder is a 16 deg² field-of-view (FoV) infrared telescope, operating in the photometric K_dark bandpass (2.35-2.5 μm). With a plate scale of 7.1′′ per 18 μm pixel on a 2048×2048 Teledyne H2RG detector array, Cryoscope Pathfinder will be the widest and deepest near-infrared imager of its kind in the K-band. A spherical primary mirror is utilized but unlike classical Schmidt designs, Cryoscope employs two fused silica meniscus lenses located on either side of the entrance pupil whereas a Schmidt telescope uses two nearly flat aspheric plates of different glass material located at a distance equal to twice the focal length from the vertex of the primary mirror. An achromatic doublet tuned to the passband delivers a flat focal plane even at large FoV. The convex meniscus element can support atmospheric pressure, allowing the entire optical path to be evacuated and cooled to 80 K to reduce thermal self-emission in a design delivering two orders of magnitude greater FoV than existing ground-based infrared telescopes. We report room temperature performance measurements, which confirm that manufacturing and alignment errors do not significantly compromise the excellent wide-field performance predicted by optical models. Interferometry in a warm bench-test setup has demonstrated on- and off-axis Strehl of 0.95 in the operating bandpass of the telescope, with co-alignment errors within ±0.2 mm. Mechanical assembly of the cryostat is now underway. Cold tests will then assess the performance of the system under vacuum and measure the thermal self-emission by capping the entrance aperture with a narcissus mirror. On-sky tests at Caltech will then be used to demonstrate focus control and PSF image quality using bright star standards over the full FoV. Cryoscope Pathfinder will be deployed to Dome C, Antarctica in December 2024 where it will benefit from infrared sky brightnesses more than 30 times darker than at temperate latitudes.

The Gamma-Ray Polarimeter (GRAPE) is a wide field of view (FoV) Compton polarimeter measuring γ-ray polarization from transient sources such as Gamma-Ray Bursts (GRBs) in the 50-500 keV energy range with a broad range (20 keV – 3 MeV) for spectroscopy. The instrument is a 7x7x5 array of 245 optically isolated SiPMs each coupled to either a high-Z (GAGG:Ce) or low-Z (para-Terphenyl) scintillator. The novel design provides enables Compton imaging in addition to polarization capabilities, and Co-60 calibration sources (~25 nCi) imbedded within two centrally located low-Z detectors allow for onboard calibrations. We will report on the instrument performance of this design during a test flight on August 27, 2023, from Fort Sumner, NM.

Our team aims to demonstrate a photonic Quantum-Inspired Imager (QI2) which provides source reconstruction below the optical/NIR diffraction limit in the presence of atmospheric turbulence without the need for adaptive optics. Turbulent cells in the atmosphere reduce image resolution by causing fluctuations in the phase of propagating wavefronts. Rather than relying on conventional methods of wavefront sensing, our approach leverages the spectral diversity inherent in the factors which limit resolution, thus breaking the degeneracy between these aberrating processes. Though this concept has long been employed in astronomy to achieve diffraction limited imaging, our approach achieves this necessary spectral diversity with a passive photonic lantern mode multiplexer that converts a multimode wavefront input into an array of spatially distinct single-mode outputs, from which we can deduce the atmospheric phase variations and reconstruct the source function. We present detailed simulations and laboratory tests demonstrating the QI2 approach in measuring atmospheric turbulence and correcting phase distortions.

The EXoplanet Climate Infrared TElescope (EXCITE) is an instrument designed to measure spectroscopic phase curves of extrasolar hot Jupiters from a long duration balloon platform. EXCITE will fly a moderate resolution spectrometer housed inside of a cryogenic receiver actively cooled by two linear pulse tube cryocoolers. Here we provide the current status of the design and performance of the cryogenic receiver, its heat rejection mechanism, and associated control electronics. A recirculating methanol fluid loop rejects heat from the cryocoolers and transports it to sky-facing radiator panels mounted to the gondola. The cryocoolers are controlled by drive electronics with active vibration reduction functionality to minimize the impact of vibrations on pointing stability. We discuss the thermal and vibrational performance of the cryogenic receiver during ground-based pointing tests in its 2023 field campaign in Ft. Sumner, NM and present its current status as EXCITE prepares for its 2024 test flight campaign.

Our project aims to identify the physical nature of gamma-ray burst (GRB) emission via measurement of the optical spectral shape of this emission during the prompt phase, usually lasting up to 70 sec. These measurements require a fast-moving optical telescope and instrumentation to respond autonomously to real-time GRB alerts. The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTellA-TAO) has a 0.7 m aperture and can point anywhere above the local horizon in 8 seconds. We receive GRB Alerts via an internet socket connection to the Gamma Coordinates Network (GCN) at the telescope site. We measure the GRB prompt optical emission with the Burst Simultaneous Three-Channel Imager (BSTI), which incorporates 3 EMCCD cameras, at Sloan g', r', and i' bands, for simultaneous high time-resolution imaging as fast as a few hundred milliseconds per frame. NUTTellA-TAO is a fully automated telescope. In 2020 and 2023, we observed GRB afterglow starting from 58 and 41 seconds after the BAT trigger. It is the earliest afterglow optical observation with three filters simultaneously.

REMIR is a NIR camera mounted on the REM telescope at ESO-La Silla Observatory. Soon after its installation in 2003, the REMIR camera went through a series of cryogenics problems, due to the bad functioning of the Leybold cryocooler Polar SC7 and we were forced to change drastically the cryogenics of REMIR, going from cryocooler to LN2, via an ad-hoc modified Continuos Flow Criostat, a cryogenics system developed by ESO. Today, the availability of new generation small cryocoolers, in our case the Sunpower CryoTel GT AVC, allowed us to change again and come back to the original cryogenics for the REMIR camera. The system has been assembled and intensively tested at ESO and at INAF-OAR premises, then it has been mounted on the REMIR camera and tested at working condition. In this paper we report the details and results of the project.

ArgusSpec, a fully autonomous low-resolution rapid follow-up spectrograph, has been optimized for stellar flare follow-up by prioritizing high speed follow-up, optical efficiency, and wavelength coverage. Stellar flares are challenging transients to follow-up at a large scale due to their spacial and temporal unpredictability and their sub-minute rise in flux followed by an exponential decay. We present performance data from commissioning along with results from operations with a real-time transient alert stream from Argus Pathfinder, located at the Pisgah Astronomical Research Institute in western North Carolina alongside ArgusSpec, and Evryscope North, housed at Mount Laguna Observatory.