SPECTROSCOPY OF FAINT KEPLER MISSION EXOPLANET CANDIDATE HOST STARS
- National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)
- NASA Ames Research Center, Moffett Field, CA 94035 (United States)
- Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)
Stellar properties are measured for a large set of Kepler mission exoplanet candidate host stars. Most of these stars are fainter than 14th magnitude, in contrast to other spectroscopic follow-up studies. This sample includes many high-priority Earth-sized candidate planets. A set of model spectra are fitted to R {approx} 3000 optical spectra of 268 stars to improve estimates of T{sub eff}, log (g), and [Fe/H] for the dwarfs in the range 4750 {<=} T{sub eff} {<=} 7200 K. These stellar properties are used to find new stellar radii and, in turn, new radius estimates for the candidate planets. The result of improved stellar characteristics is a more accurate representation of this Kepler exoplanet sample and identification of promising candidates for more detailed study. This stellar sample, particularly among stars with T{sub eff} {approx}> 5200 K, includes a greater number of relatively evolved stars with larger radii than assumed by the mission on the basis of multi-color broadband photometry. About 26% of the modeled stars require radii to be revised upward by a factor of 1.35 or greater, and modeling of 87% of the stars suggest some increase in radius. The sample presented here also exhibits a change in the incidence of planets larger than 3-4 R{sub Circled-Plus} as a function of metallicity. Once [Fe/H] increases to {>=} - 0.05, large planets suddenly appear in the sample while smaller planets are found orbiting stars with a wider range of metallicity. The modeled stellar spectra, as well as an additional 84 stars of mostly lower effective temperatures, are made available to the community.
- OSTI ID:
- 22140135
- Journal Information:
- Astrophysical Journal, Vol. 771, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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