SPECTRE is a proposed 0.4-4.2 µm low-resolution spectrograph being developed for the NASA Infrared Telescope Facility. Dispersion is accomplished using prisms to optimize throughput, resulting in a mean resolving power of R=160. SPECTRE has an image-slicer integral field unit with a 7.2′′ field of view to remove slit losses, reduce mechanical complexity, and enable precision spectrophotometry. Dichroics are used to divide the light into three spectroscopic channels, each with optimized optics and its own detector. We will use a 2K frame transfer CCD for the optical channel, and an H2RG in each of the two infrared channels. SPECTRE is a single mode instrument: there are no moving optics and the spectral format is fixed, making for a simple and rigid instrument. Guiding will be done by a co-mounted visible light camera with a 3′ field of view.
‘Opihi is a 0.43 m, 32′ field of view (FOV) finder scope that rides along with the NASA Infrared Telescope Facility (IRTF), a 3.2 m infrared-optimized telescope near the summit of Mauna Kea, Hawai‘i. The main purpose of ‘Opihi is to recover Near-Earth Objects (NEOs) with positional uncertainties larger than can feasibly be found with the 1 ′ FOV of IRTF. Automated data collection with ‘Opihi will be useful for bootstrap photometry and can provide general context observing images. We present the design and commissioning process for ‘Opihi, including its photometric performance and first asteroid detection results
We are building a next-generation laser adaptive optics system, Robo-AO-2, for the UH 2.2-m telescope that will deliver robotic, diffraction-limited observations at visible and near-infrared wavelengths in unprecedented numbers. The superior Maunakea observing site, expanded spectral range and rapid response to high-priority events represent a significant advance over the prototype. Robo-AO-2 will include a new reconfigurable natural guide star sensor for exquisite wavefront correction on bright targets and the demonstration of potentially transformative hybrid AO techniques that promise to extend the faintness limit on current and future exoplanet adaptive optics systems.
iSHELL is 1.10-5.3 μm high spectral resolution spectrograph being built for the NASA Infrared Telescope Facility on Maunakea, Hawaii. Dispersion is accomplished with a silicon immersion grating in order to keep the instrument small enough to be mounted at the Cassegrain focus of the telescope. The white pupil spectrograph produces resolving powers of up to R=75,000. Cross-dispersing gratings mounted in a tilt-able mechanism allow observers to select different wavelength ranges and, in combination with a slit wheel and Dekker mechanism, slit lengths ranging from 5ʺ″ to 25ʺ″. One Teledyne 2048x2048 Hawaii 2RG array is used in the spectrograph, and one Raytheon 512x512 Aladdin 2 array is used in a slit viewer for object acquisition and guiding. First light is expected in mid-2016. In this paper we discuss details of the construction, assembly and laboratory testing.
The prototype Robo-AO system at the Palomar Observatory 1.5-m telescope is the world's first fully automated laser adaptive optics instrument. Scientific operations commenced in June 2012 and more than 12,000 observations have since been performed at the ~0.12" visible-light diffraction limit. Two new infrared cameras providing high-speed tip-tilt sensing and a 2' field-of-view will be integrated in 2014. In addition to a Robo-AO clone for the 2-m IGO and the natural guide star variant KAPAO at the 1-m Table Mountain telescope, a second generation of facility-class Robo-AO systems are in development for the 2.2-m University of Hawai'i and 3-m IRTF telescopes which will provide higher Strehl ratios, sharper imaging, ~0.07", and correction to λ = 400 nm.
Direct imaging of extrasolar planets in visible light, and Earth-like planets in particular, is an exciting but difficult problem requiring a telescope imaging system with 10-10 contrast at separations of 100mas and less. Furthermore, only a small 1-2m space telescope may be realistic for a mission in the foreseeable future, which puts strong demands on the performance of the imaging instrument. Fortunately, an efficient coronagraph called the Phase Induced Amplitude Apodization (PIAA) coronagraph may enable Earth-like planet imaging for such small telescopes if any exist around the nearest stars. In this paper, we report on the latest results from a testbed at the NASA Ames Research Center focused on testing the PIAA coronagraph. This laboratory facility was built in 2008 and is designed to be flexible, operated in a highly stabilized air environment, and to complement efforts at NASA JPL's High Contrast Imaging Testbed. For our wavefront control we are focusing on using small Micro-Electro-Mechanical-System deformable mirrors (MEMS DMs), which promises to reduce the size of the beam and overall instrument, a consideration that becomes very important for small telescopes. In this paper, we briefly describe our lab and methods, including the new active thermal control system, and report the demonstration of 5.4×10-8 average raw contrast in a dark zone from 2.0 - 5.2 λ/D. In addition, we present an analysis of our current limits and solutions to overcome them.
Direct imaging of extrasolar planets, and Earth-like planets in particular, is an exciting but difficult problem requiring a
telescope imaging system with 1010 contrast at separations of 100mas and less. Furthermore, the current NASA science
budget may only allow for a small 1-2m space telescope for this task, which puts strong demands on the performance of
the imaging instrument. Fortunately, an efficient coronagraph called the Phase Induced Amplitude Apodization (PIAA)
coronagraph has been maturing and may enable Earth-like planet imaging for such small telescopes. In this paper, we
report on the latest results from a new testbed at NASA Ames focused on testing the PIAA coronagraph. This laboratory
facility was built in 2008 and is designed to be flexible, operated in a highly stabilized air environment, and to
complement existing efforts at NASA JPL. For our wavefront control we are focusing on using small Micro-Electro-
Mechanical-System deformable mirrors (MEMS DMs), which promises to reduce the size of the beam and overall
instrument, a consideration that becomes very important for small telescopes. At time of this writing, we are operating a
refractive PIAA system and have achieved contrasts of about 1.2x10-7 in a dark zone from 2.0 to 4.8 λ/D (with 6.6x10-8
in selected regions). In this paper, we present these results, describe our methods, present an analysis of current limiting
factors, and solutions to overcome them.
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