The number of type Ia supernova observations will see significant growth within the next decade, especially thanks to the Legacy Survey of Space and Time (LSST) undertaken by the Vera Rubin Observatory in Chile. With this improvement, statistical uncertainties will decrease and flux calibration will be one of the dominant sources of systematic uncertainties for the characterization of dark energy. To address this issue, the StarDICE experiment proposes to recalibrate the spectra of CALSPEC standards stars at the millimagnitude level, securing calibration reference for any SNe Ia survey. The StarDICE experiment is currently operating at l’Observatoire de Haute-Provence and has been taking data since the beginning of 2023. To reach a sub-percent precision, the instrument throughput will be monitored with an LED-based artificial star source, calibrated on NIST photodiodes. I present here the first results of the StarDICE photometric analysis, and the predicted performance to recalibrate the CALSPEC standard stars.
Cosmic explosions have emerged as a major field of astrophysics over the last years with our increasing capability to monitor large parts of the sky in different wavelengths and with different messengers (photons, neutrinos, and gravitational waves). In this context, gamma-ray bursts (GRBs) play a very specific role, as they are the most energetic explosions in the Universe. The forthcoming Sino-French SVOM mission will make a major contribution to this scientific domain by improving our understanding of the GRB phenomenon and by allowing their use to understand the infancy of the Universe. In order to fulfill all of its scientific objectives, SVOM will be complemented by a fast robotic 1.3 m telescope, COLIBRI, with multiband photometric capabilities (from visible to infrared). This telescope is being jointly developed by France and Mexico. The telescope and one of its instruments are currently being extensively tested at OHP in France and will be installed in Mexico in spring 2023.
The Provence Adaptive optics Pyramid Run System (PAPYRUS) is a pyramid-based Adaptive Optics (AO) system that will be installed at the Coude focus of the 1.52m telescope (T152) at the Observatoire de Haute Provence (OHP). The project is being developed by PhD students and Postdocs across France with support from staff members consolidating the existing expertise and hardware into an RD testbed. This testbed allows us to run various pyramid wavefront sensing (WFS) control algorithms on-sky and experiment on new concepts for wavefront control with additional benefit from the high number of available nights at this telescope. It will also function as a teaching tool for students during the planned AO summer school at OHP. To our knowledge, this is one of the first pedagogic pyramid-based AO systems on-sky. The key components of PAPYRUS are a 17x17 actuators Alpao deformable mirror with a Alpao RTC, a very low noise camera OCAM2k, and a 4-faces glass pyramid. PAPYRUS is designed in order to be a simple and modular system to explore wavefront control with a pyramid WFS on sky. We present an overview of PAPYRUS, a description of the opto-mechanical design and the current status of the project.
The recently commissioned Dark Energy Spectroscopic Instrument (DESI) will measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 sqdeg will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope delivers light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. A consortium of Aix-Marseille University (AMU) and CNRS laboratories (LAM, OHP and CPPM) together with LPNHE (CNRS, IN2P3, Sorbonne Université and Université de Paris) and the WINLIGHT Systems company based in Pertuis (France), were in charge of integrating and validating the performance requirements of the ten full spectrographs, equipped with their cryostats, shutters and other mechanisms. We present a summary of our activity which allowed an efficient validation of the systems in a short-time schedule. We detail the main results. We emphasize the benefits of our approach and also its limitations.
We present an overview of the development of the end-to-end simulations programs developed for COLIBRI (Catching OpticaL and Infrared BRIght), a 1.3m robotic follow-up telescope of the forthcoming SVOM (Space Variable Object Monitor) mission dedicated to the detection and study of gamma-ray bursts (GRBs). The overview contains a description of the Exposure Time Calculator, Image Simulator and photometric redshift code developed in order to assess the performance of COLIBRI. They are open source Python packages and were developed to be easily adaptable to any optical/ Near-Infrared imaging telescopes. We present the scientific performances of COLIBRI, which allows detecting about 95% of the current GRB dataset. Based on a sample of 500 simulated GRBs, a new Bayesian photometric redshift code predicts a relative photometric redshift accuracy of about 5% from redshift 3 to 7.
COLIBRI is one of the two robotic ground follow-up telescopes for the SVOM (Space Variable Object Monitor) mission dedicated to the study of gamma-ray bursts, allowing determination of precise celestial coordinates of the detected bursts. COLIBRI telescope is a two-mirror Ritchey-Chrétien telescope whose concave primary and convex secondary mirrors have diameters of 1325mm and 485mm respectively. The mirrors are currently manufactured at LAM (Laboratoire d’Astrophysique de Marseille). In this article, the advancement of the work is presented. We also give a global overview and status of the COLIBRI project.
The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 deg² will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. A consortium of Aix-Marseille University (AMU) and CNRS laboratories (LAM, OHP and CPPM) together with LPNHE (CNRS, Universities Pierre et Marie Curie and Paris-Diderot) and the WINLIGHT Systems company based in Pertuis (France), are in charge of integrating and validating the performance requirements of the full spectrographs. This includes the cryostats, shutters and other mechanisms. The first spectrograph of the series of ten has been fully tested and the performance requirements verified for the following items: focus, image quality, straylight, stability, detector properties and throughput. We present the experimental setup, the test procedures and the results.
We present in this article some of the techniques applied at the Instituto de Astronomía of the Universidad Nacional Autónoma de México (IA-UNAM) to the mechanical structural design for astronomical instruments. With this purpose we use two recent projects developed by the Instrumentation Department. The goal of this work is to give guidelines about support structures design for achieving a faster and accurate astronomical instruments design. The main guidelines that lead all the design stages for instrument subsystems are the high-level requirements and the overall specifications. From these, each subsystem needs to get its own requirements, specifications, modes of operation, relative position, tip/tilt angles, and general tolerances. Normally these values are stated in the error budget of the instrument. Nevertheless, the error budget is dynamic, it is changing constantly. Depending on the manufacturing accuracy achieved, the error budget is again distributed. That is why having guidelines for structural design helps to know some of the limits of tolerances in manufacture and assembly. The error budget becomes then a quantified way for the interaction between groups; it is the key for teamwork.
The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation probe. The KPNO Mayall telescope will deliver light to 5000 fibers feeding ten broadband spectrographs. A consortium of Aix-Marseille University (AMU) and CNRS laboratories (LAM, OHP and CPPM) together with the WINLIGHT Systems company (Pertuis-France) has committed to integrate and validate the performance requirements of the full spectrographs, equipped with their cryostats, shutters and other mechanisms. An AIT plan has been defined and dedicated test equipment has been designed and implemented. This equipment simulates the fiber input illumination from the telescope, and offers a variety of continuum and line sources. Flux levels are adjustable and can illuminate one or several fibers along the test slit. It is fully remotely controlled and interfaced to the Instrument Control System. Specific analysis tools have also been developed to verify and monitor the performance and stability of the spectrographs. All these developments are described in details.
L. Abe, J.-P. Rivet, A. Agabi, E. Aristidi, D. Mekarnia, I. Goncalves, T. Guillot, M. Barbieri, N. Crouzet, F. Fressin, F.-X. Schmider, Y. Fantei-Caujolle, J.-B. Daban, C. Gouvret, S. Peron, P.-Y. Petit, A. Robini, M. Dugue, E. Bondoux, T. Fruth, A. Erikson, H. Rauer, F. Pont, A. Alapini, S. Aigrain, J. Szulagyi, P.-E. Blanc, A. Le Van Suu
The ASTEP program is dedicated to exo-planet transit search from the Concordia Station located at Dome C, Antarctica.
It comprises two instruments: a fixed 10cm refractor pointed toward the celestial South Pole, and a 400mm Newton
telescope with a 1x1 degree field of view. This work focuses on the latter instrument. It has been installed in November
2009, and has been observing since then during the two polar winters 2010 and 2011. After presenting the main science
observing programs, we review the telescope installation, performance, and describe its operating conditions as well as
the data reduction and handling strategy. The resulting lightcurves are generally very stable and of excellent quality, as
shown by continuous observations of WASP-19 that we present here.
We have built at the Haute-Provence observatory (France) the rst diluted telescope in the world. We describe
this prototype called Carlina, made of three 25 cm mirrors separated by a maximum baseline of 10.5 m. The
three mirrors in place are already coherenced and rst light is scheduled for June-July 2012. In this article, we
will mainly describe the focal gondola. We propose to build in the near future a 100 m aperture Large Diluted
Telescope. This diluted telescope will be more sensitive than regular interferometers (Keck, VLTI, etc.), with
higher imaging capabilities. A LDT will open new elds of research in astrophysics thanks to very high angular
resolution imaging of the surface of supergiant stars, AGN, gravitational micro-lens systems, exo-planets, etc.
The Concordia Base in Dome C, Antarctica, is an extremely promising site for photometric astronomy due to the 3-
month long night during the Antarctic winter, favorable weather conditions, and low scintillation. The ASTEP project
(Antarctic Search for Transiting ExoPlanets) is a pilot project which seeks to identify transiting planets and understand
the limits of visible photometry from this site. ASTEP 400 is an optical 40cm telescope with a field of view of 1° x 1°.
The expected photometric sensitivity is 1E-3, per hour for at least 1,000 stars. The optical design guarantees high
homogeneity of the PSF sizes in the field of view. The use of carbon fibers in the telescope structure guarantees high
stability. The focal optics and the detectors are enclosed in a thermally regulated box which withstands extremely low
temperatures. The telescope designed to run at -80°C (-110°F) was set up at Dome C during the southern summer 2009-
2010. It began its nightly observations in March 2010.
ELP-OA ('Etoile Laser Polychromatique pour l'Optique Adaptative) aims at demonstrating the tip-tilt is measurable
with a Laser Guide Star (LGS) without any natural guide star. This allows a full sky coverage down to
visible wavelengths. ELP-OA is being setup at Observatoire de
Haute-Provence (OHP). To create a polychromatic
LGS, we use two pulsed dye lasers (at 569nm and 589nm) to produce a two-photons excitation of sodium
atoms in the mesosphere. The chromatism of the refractive index of the air yields a difference of the LGS
direction at different wavelengths. The position differences is proportionnal to the tip-tilt. Since the LGS isn't
sharp enough to give us a small enough error in the differential
tip-tilt, we use an interferometric projector to
improve the high spatial information in the laser spot. It requires an adaptive optics working down to 330nm.
This one is done by post-processing algorithms. Two two aperture projectors are used. Each one creates a
fringe-modulated LGS, and a better RMS error in the LGS position is obtained by measuring the information
in a normal direction with respect to the fringes. By using a two aperture projector, we also strongly decrease
the negative effect of the laser star elongation in the mesosphere, and the Rayleigh contribution near the LGS.
We propose a new optimal algorithm to retrieve the tip-tilt from simultaneous images at different wavelengths.
To enhance the RMS error of the measurements, we extend this algorithm to exploit the temporal correlation
of the turbulence.
We discuss our Polychromatic Laser Guide Star (PLGS) end-to-end model which relies on the 2-photon
excitation of sodium in the mesosphere. We then describe the status of the setup at Observatoire de Haute-
Provence of ELP-OA, the (PLGS) concept demonstrator. The PLGS aims at measuring the tilt from the LGS
without any NGS. Two dye laser chains locked at 589 and 569nm are required. These chains, are similar to those
of our PASS-2 experiment at Pierrelatte (1999). The two oscillators, preamplifiers and amplifiers are pumped
with NdYAGs. Both beams are phase modulated with a double sine function. If required, a third stage can
be added. It is expected that beams will deliver an output average power of 34W each, so that 22W will be
deposited into the mesosphere. If it is not enough, there is enough power supply to twofold it.
These lasers are being settled in the building of the OHP 1.52m telescope, partly at the first floor, and partly
at the top of the North pillar. Beams will propagate from there to the launch telescope attached to the 1.52m
one through a train of mirrors fixed with respect to the beam, so that incident angles are constant.
The coudé focus of the 1.52m telescope will be equipped with an adaptive optics device, closely derived from
the ONERA's BOA one. The Strehl ratio at 330nm for the differential tilt measurement channel is expected to
be 30-40% for r0 = 8 - 10cm. Telescope vibrations will be measured with pendular seismometers upgraded from Tokovinin's prototype. The full demonstrator is planned to run in 2010.
The Polychromatic Laser Guide Star aims at providing for the tilt measurement from a LGS without any
natural guide star. Thus it allows adaptive optics to provide us with a full sky coverage. This is critical in
particular to extend adaptive optics to the visible range, where isoplanatism is so small that the probability is
negligible to find a natural star to measure the tilt.
We report new results obtained within the framework of the Polychromatic LGS programme ELP-OA. Natural
stars have been used to mimic the PLGS, in order to check the feasibility of using the difference in the tilt at
two wavelengths to derive the tilt itself. We report results from the ATTILA experiment obtained at the 1.52 m
telescope at Observatoire de Haute-Provence. Tilts derived from the differential tilts are compared with direct
tilt measurements. The accuracy of the measurements is currently ≈ 1.5 Airy disk rms at 550 nm. These results
prove the feasibility of the Polychromatic Laser Guide Star programme ELP-OA. New algorithms based on
inverse problems under development within our programme would lead to smaller error bars by 1 magnitude,
as soon as they will run fast enough.
We describe the ELP-OA demonstrator which we are setting up at the same telescope, with a special emphasis
on the optimization of the excitation process, which definitely has to rely on the two-photon excitation of sodium
atoms in the mesosphere. We will describe the implementation at the telescope, including the projector device,
the focal instrumentation and the NdYAG pumped dye lasers.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.