Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a thorium argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to twelve 1-meter telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect our first spectrograph to be deployed in fall 2016, with the full network operation of 5 or 6 units beginning in 2017. We will briefly overview the NRES design, goals, robotic operation, and status. In addition, we will discuss early results from our prototype spectrograph, the laboratory and on-sky performance of our first production unit, and the ongoing software development effort to bring this resource online.
We present the design and development of the DEdicatedMONitor of EXotransits and Transients (DEMONEXT), an automated and robotic 20 inch telescope jointly funded by The Ohio State University and Vanderbilt University. The telescope is a PlaneWave CDK20 f/6.8 Corrected Dall-Kirkham Astrograph telescope on a Mathis Instruments MI-750/1000 Fork Mount located atWiner Observatory in Sonoita, AZ. DEMONEXT has a Hedrick electronic focuser, Finger Lakes Instrumentation (FLI) CFW-3-10 filter wheel, and a 2048 x 2048 pixel FLI Proline CCD3041 camera with a pixel scale of 0.90 arc-seconds per pixel and a 30.7× 30.7 arc-minute field-of-view. The telescope’s automation, controls, and scheduling are implemented in Python, including a facility to add new targets in real time for rapid follow-up of time-critical targets. DEMONEXT will be used for the confirmation and detailed investigation of newly discovered planet candidates from the Kilodegree Extremely Little Telescope (KELT) survey, exploration of the atmospheres of Hot Jupiters via transmission spectroscopy and thermal emission measurements, and monitoring of select eclipsing binary star systems as benchmarks for models of stellar evolution. DEMONEXT will enable rapid confirmation imaging of supernovae, flare stars, tidal disruption events, and other transients discovered by the All Sky Automated Survey for SuperNovae (ASAS-SN). DEMONEXT will also provide follow-up observations of single-transit planets identified by the Transiting Exoplanet Survey Satellite (TESS) mission, and to validate long-period eclipsing systems discovered by Gaia.
The Miniature Exoplanet Radial Velocity Array (MINERVA) is a U.S.-based observational facility dedicated to the discovery and characterization of exoplanets around a nearby sample of bright stars. MINERVA employs a robotic array of four 0.7-m telescopes outfitted for both high-resolution spectroscopy and photometry, and is designed for completely autonomous operation. The primary science program is a dedicated radial velocity survey and the secondary science objective is to obtain high-precision transit light curves. The modular design of the facility and the flexibility of our hardware allows for both science programs to be pursued simultaneously, while the robotic control software provides a robust and efficient means to carry out nightly observations. We describe the design of MINERVA, including major hardware components, software, and science goals. The telescopes and photometry cameras are characterized at our test facility on the Caltech campus in Pasadena, California, and their on-sky performance is validated. The design and simulated performance of the spectrograph is briefly discussed as we await its completion. New observations from our test facility demonstrate sub-mmag photometric precision of one of our radial velocity survey targets, and we present new transit observations and fits of WASP-52b—a known hot-Jupiter with an inflated radius and misaligned orbit. The process of relocating the MINERVA hardware to its final destination at the Fred Lawrence Whipple Observatory in southern Arizona has begun, and science operations are expected to commence in 2015.
Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by two 1 meter telescopes and a thorium argon calibration source, one at each of our observatory sites in the Northern and Southern hemispheres. Thus, NRES will be a single, globally-distributed, autonomous observing facility using twelve 1-m telescopes. Simulations suggest we will achieve long-term precision of better than 3 m/s in less than an hour for stars brighter than V = 12. We have been fully funded with an NSF MRI grant, and expect our first spectrograph to be deployed in Spring of 2015, with the full network operation of all 6 units beginning in Spring of 2016. We discuss the NRES design, goals, and robotic operation, as well as the early results from our prototype spectrograph.
The DEdicated MONitor of EXotransits (DEMONEX) is a low-cost, 0.5 meter, robotic telescope assembled
mostly from commercially-available parts. The primary goal of DEMONEX is to monitor bright stars hosting
transiting planets in order to provide a homogeneous data set of precise relative photometry for all transiting
systems visible from its location at Winer Observatory in Sonoita, Arizona. This photometry will be used to refine
the planetary parameters, search for additional planets via transit timing variations, place limits on the emission
of the planet from secondary eclipses, and search for additional transiting planets in some systems. Despite its
modest size, DEMONEX achieves a signal-to-noise ratio per transit that is comparable to that obtained with
larger, 1m-class telescopes, because of its short readout time and high z-band quantum efficiency. However, the
main advantage of DEMONEX is that it can be used every night for transit follow-up. With the 39 known
transiting planets visible from Winer Observatory, over 90% of all nights have at least one full event to observe.
We describe the hardware, and the scheduling, observing, and data reduction software, and we present some
results from the first two years of operation. Synoptic surveys coming online will undoubtedly uncover a plethora
of variable objects which will require inexpensive, robotic, dedicated telescopes to adequately characterize. The
outline followed and lessons learned from this project will be broadly applicable for constructing such facilities.
We discuss the application of modern precision electroforming technology to the fabrication of multi-slit masks used for multi-object spectroscopy. Electroforming technology is capable of producing very accurate compound curved thin metal shells using nickel or nickel-cobalt material. The curved slit masks can be fabricated to conform to a curved focal surface of spherical, conic, or arbitrary shape. A variety of optical coatings including gold and extremely low reflectivity copper oxide can be applied to the electroformed mask substrate prior to cutting slits. Precise rectangular slits and apertures of arbitrary shape are readily machined in the nickel materials using a three axis YAG laser machining system.
We discuss the performance of the Image Motion Compensation System (IMCS) for the Multi-Object Double Spectrograph (MODS). The system performs closed-loop image motion compensation, actively correcting for image motion in the spectrograph's focal plane caused by large scale structural bending due to gravity as well as other effects such as temperature fluctuation and mechanism flexure within the instrument. Not only does the system control instrumental flexure to within the specifications (0.1 pixels on the science CCD, or 1.5 μm), but it also has proven to be an excellent diagnostic tool for assembling and testing the spectrograph. We describe both the final performance of the system as deployed in the spectrograph as well as the instrumental tests made possible by the IMCS.
Ohio State is building two identical Multi-Object Double Spectrographs (MODS), one for each of the f/15 Gregorian foci of the Large Binocular Telescope (LBT). Each MODS is a high-throughput optical low- to medium-resolution CCD spectrometer operating in the 320-1000nm range with a 6.5-arcminute field-of-view. A dichroic distributes the science beam into separately-optimized red and blue channels that provide for direct imaging and up to 3 spectroscopic modes per channel. The identical MODS instruments may be operated together with digital data combination as a single instrument giving the LBT an effective aperture of 11.8-meter, or separately configured to flexibly use the twin 8.4-meter apertures. This paper describes progress on the integration and testing of MODS1, and plans for the deployment of MODS2 by the end of 2008 at the LBT.