NOAO >   Observing Info >   Approved Programs >   2010B-0534

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Proposal Information for 2010B-0534


PI: Ji Wang, jwang@astro.ufl.edu
Address: 211 Bryant Space Science Center, Gainesville

CoI: Jian Ge
CoI: Scott Fleming
CoI: Bo Ma

Title: Searching For Planets Around M Dwarfs with EXPERT

Abstract: Planets around M dwarfs are of great scientific interest for several reasons: 1) M dwarfs make up 70% of the stars in the Milky Way and the solar neighborhood and yet only 16 planets have been discovered around these stars. 2) The radial velocity (RV) signal is larger than that around solar type stars due to their lower stellar masses for the same orbital parameters of surrounding planets. 3) The habitable zone is closer to the host star compared to solar type stars due to their much lower luminosity. We propose to use EXPERT (EXtremely high Precision ExtrasolaR planet Tracker) in DEM (Direct Echelle Mode) to measure radial velocities of 41 M3.5-M6 dwarfs over one-year baseline. This sample is about 1.5 times larger than the combined sample of similar surveys in the past. Our simulations show that we can achieve RV precision of ~3 m/s in DEM of EXPERT at the Kitt Peak 2.1m when observing slow rotating M dwarfs (vsini<3 km/s). The spectral resolution of DEM is 27,000 and the wavelength coverage is from 3900\AA\ to 10000\AA. Our proposed observations will help to address the following key questions and constrain planetary formation model: What is the planet occurrence rate around mid to late type M dwarfs? Are close- in Jupiter-like planets less probable while Neptune-like planets are more probable around M dwarfs than solar type stars? In order to reach our required Doppler precision, we will look for an optimal strategy to remove telluric line contamination in the near IR wavelengths. We also plan to use a new RV calibration source using white light combs produced by a thermally-stable interferometer instead of a ThAr lamp to further increase our RV calibration accuracy. Data collected in this project will be part of the Ph.D thesis for Ji Wang.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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