On-sky Doppler Performance of TOU Optical Very High Resolution Spectrograph for Detecting Low-Mass Planets Jian Ge, Bo Ma, Sirinrat Sithajan, Michael A. Singer, Scott Powell, Frank Varosi, Bo Zhao, Sidney Schofield, Jian Liu, Nolan Grieves, Anthony Cassette, Louis Avner & Hali Jakeman Department of Astronomy, University of Florida Matthew Muterspaugh & Michael Williamson Center of Excellence in Information Systems, Tennessee State University Rory Barnes Department of Astronomy, University of Washington Email: jge@astro.ufl.edu The TOU robotic, compact very high resolution optical spectrograph (R=100,000, 0.38-0.9 microns) has been fully characterized at the 2 meter Automatic Spectroscopy Telescope (AST) at Fairborn Observatory in Arizona during its pilot survey of 12 bright FGK dwarfs in 2015. This instrument has delivered sub m/s Doppler precision for bright reference stars (e.g., 0.7 m/s for Tau Ceti over 60 days) with 5-30 min exposures and 0.7 m/s long-term instrument stability, which is the best performance among all of the known Doppler spectrographs to our knowledge. This performance was achieved by maintaining the instrument in a very high vacuum of 1 micron torr and about 0.5 mK (RMS) long-term temperature stability through an innovative close-loop instrument bench temperature control. It has discovered a 21 Earth-mass planet (P=43days) around a bright K dwarf and confirmed three super-Earth planetary systems, HD 1461, 190360 and HD 219314. This instrument will be used to conduct the Dharma Planet Survey (DPS) in 2016-2019 to monitor ~100 nearby very bright FGK dwarfs (most of them brighter than V=8) at the dedicated 50-inch Robotic Telescope on Mt. Lemmon. With very high RV precision and high cadence (~100 observations per target randomly spread over 450 days), a large number of rocky planets, including possible habitable ones, are expected to be detected. The survey also provides the largest single homogenous high precision RV sample of nearby stars for studying low mass planet populations and constraining various planet formation models. Instrument on-sky performance is summarized. Key words: Doppler, exoplanets, high cadence, survey, high spectral resolution, optical spectrograph, FGK dwarfs and high precision 1. Introduction The discovery of the hot Jupiter around 51 Peg in 1995 using Doppler spectroscopy has triggered the start of an intensive era of discoveries of exoplanets. Since the launch of the Kepler space satellite in 2009, Kepler transit search has made a major breakthrough in identifying thousands of low-mass planet candidates while significantly improving statistical study of the exoplanetary systems 1 . To date, a total of 1642 planets have been confirmed while 3787 Kepler planet candidates have yet to be confirmed (http://exoplanets.org). Transit detections (1147 planets, the majority by Kepler) and Doppler techniques (470 planets) contributed the most to these discoveries. Today, the main focus for Ground-based and Airborne Instrumentation for Astronomy VI, edited by Christopher J. Evans, Luc Simard, Hideki Takami Proc. of SPIE Vol. 9908, 99086I · © 2016 SPIE · CCC code: 0277-786X/16/$18 · doi: 10.1117/12.2232217 Proc. of SPIE Vol. 9908 99086I-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 12/15/2016 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx