Journal Article

Precise Stellar Radial Velocities of an M Dwarf with a Michelson Interferometer and a Medium-Resolution Near-Infrared Spectrograph

Mercer, Tony, Hamren, Katherine, Erskine, David J., Halverson, Samuel P., Andelson, Phillip, Czeszumska, Agnieszka, Vanderburg, Andrew, Mondo, Daniel, Covey, Kevin R., Wishnow, Edward H., Wright, Jason T., Muterspaugh, Matthew W., Muirhead, Philip S., Kimber, David, Lloyd, James P., Edelstein, Jerry

2011

Overview

Precise near-infrared radial velocimetry enables efficient detection and transit verification of low-mass extrasolar planets orbiting M-dwarf hosts, which are faint for visible-wavelength radial velocity surveys. The TripleSpec Exoplanet Discovery Instrument (TEDI) is the combination of a variable-delay Michelson interferometer and a medium-resolution ( R = 2700 R = 2700 ) near-infrared spectrograph on the Palomar 200 inch (5 m) Hale Telescope. We used TEDI to monitor GJ 699, a nearby mid-M dwarf, over 11 nights spread across 3 months. Analysis of 106 independent observations reveals a root-mean-squared precision of less than37 m s-1 37     m   s - 1 for 5 minutes of integration time. This performance is within a factor of 2 of our expected photon-limited precision. We further decompose the residuals into a33 m s-1 33     m   s - 1 white noise component and a15 m s-1 15     m   s - 1 systematic noise component, which we identify as being likely due to contamination by telluric absorption lines. With further development this technique holds promise for broad implementation on medium-resolution near-infrared spectrographs to search for low-mass exoplanets orbiting M dwarfs and to verify low-mass transit candidates.

• Publisher: University of Chicago Press
• Subject: Astronomy / Earth, ocean, space / Exact sciences and technology