Modeling Multi-wavelength Stellar Astrometry. II. Determining absolute inclinations, gravity-darkening coefficients, and spot parameters of single stars with SIM lite
Abstract
We present a novel technique to determine the absolute inclination of single stars using multi-wavelength sub-milliarcsecond astrometry. The technique exploits the effect of gravity darkening, which causes a wavelength-dependent astrometric displacement parallel to a star's projected rotation axis. We find that this effect is clearly detectable using SIM Lite for various giant stars and rapid rotators, and present detailed models for multiple systems using the reflux code. We also explore the multi-wavelength astrometric reflex motion induced by spots on single stars. We find that it should be possible to determine spot size, relative temperature, and some positional information for both giant and nearby main-sequence stars utilizing multi-wavelength SIM Lite data. These data will be extremely useful in stellar and exoplanet astrophysics, as well as supporting the primary SIM Lite mission through proper multi-wavelength calibration of the giant star astrometric reference frame, and reduction of noise introduced by starspots when searching for extrasolar planets.
Additional Information
© 2010 The American Astronomical Society. Received 2010 May 6; accepted 2010 September 8; published 2010 October 21. This work was sponsored in part by a SIM Science Study (PI: D. Gelino) from the National Aeronautics and Space Administration through a contract with the Jet Propulsion Laboratory, California Institute of Technology. J.L.C. acknowledges additional support from a New Mexico Space Grant Consortium Fellowship. We thank the referee for comments which greatly helped to improve this manuscript, particularly in making the presentation of our ideas much clearer.Attached Files
Published - Coughlin2010p12060Astrophys_J.pdf
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Additional details
- Eprint ID
- 21231
- Resolver ID
- CaltechAUTHORS:20101208-084207401
- NASA/JPL/Caltech
- New Mexico Space Grant Consortium
- Created
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2010-12-08Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)