2004/10/20 by A. Sozzetti, David Yong, D. Yong +14 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/426864
published as Astrophys.J. 616 (2004) L167-L170 · 14 pages, 3 figures, Astrophysical Journal Letters, accepted
arxiv created 2004/10/20 · openalex publication_date 2004/10/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
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 T eff = 5250 ± 75 K, log g = 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 M ☉ and R ⋆ = 0.83 ± 0.05 R ☉ . Our improved estimates of the stellar parameters are utilized in a new analysis of the transit photometry of TrES-1 to derive a mass M p = M J , a radius R p = 1.04 R J , and an inclination i = 89.5 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.