High-Resolution Spectroscopy of the Transiting Planet Host Star TrES-1
Abstract
We report on a spectroscopic determination of the stellar parameters and chemical abundances for the parent star of the transiting planet TrES-1. Based on a detailed analysis of iron lines in our Keck and Hobby-Eberly Telescope spectra, we derive Teff=5250+/-75 K, logg=4.6+/-0.2, and [Fe/H]=0.00+/-0.09. By measuring the Ca II activity indicator and by putting useful upper limits on the Li abundance, we constrain the age of TrES-1 to be 2.5+/-1.5 Gyr. By comparing theoretical stellar evolution models with the observational parameters, we obtain M*=0.89+/-0.05 Msolar and R*=0.83+/-0.05 Rsolar. Our improved estimates of the stellar parameters are utilized in a new analysis of the transit photometry of TrES-1 to derive a mass Mp=(0.76+/-0.05)MJ, a radius Rp=1.04+0.08-0.05RJ, and an inclination i=89.5+0.5-1.3 deg. The improved planetary mass and radius estimates provide the grounds for new crucial tests of theoretical models of evolution and evaporation of irradiated extrasolar giant planets.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2004
- DOI:
- 10.1086/426864
- arXiv:
- arXiv:astro-ph/0410483
- Bibcode:
- 2004ApJ...616L.167S
- Keywords:
-
- Stars: Planetary Systems: Formation;
- Stars: Abundances;
- Stars: Individual: Alphanumeric: TrES-1;
- Astrophysics
- E-Print:
- 14 pages, 3 figures, Astrophysical Journal Letters, accepted