Starspot Jitter in Photometry, Astrometry, and Radial Velocity Measurements
Abstract
Analytical relations are derived for the amplitude of astrometric, photometric, and radial velocity (RV) perturbations caused by a single rotating spot. The relative power of the starspot jitter is estimated and compared with the available data for κ^1 Ceti and HD 166435, as well as with numerical simulations for κ^1 Ceti and the Sun. A Sun-like star inclined at i = 90° at 10 pc is predicted to have an rms jitter of 0.087 μas in its astrometric position along the equator, and 0.38 m s^(–1) in radial velocities. If the presence of spots due to stellar activity is the ultimate limiting factor for planet detection, the sensitivity of SIM Lite to Earth-like planets in habitable zones is about an order of magnitude higher than the sensitivity of prospective ultra-precise RV observations of nearby stars.
Additional Information
© 2009 The American Astronomical Society. Received 2009 September 28; accepted 2009 November 9; published 2009 November 24. The authors thank G. Walker for his detailed and helpful review. The research described in this Letter was in part carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This research has made use of the NStED database, maintained at NExScI, Pasadena, USA.Attached Files
Published - Makarov2009p6581Astrophys_J_Lett.pdf
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- Eprint ID
- 17006
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- CaltechAUTHORS:20091218-145920085
- NASA
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2009-12-23Created from EPrint's datestamp field
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2021-11-08Created from EPrint's last_modified field