1999/11/23 by David Charbonneau, Timothy M. Brown, David W. Latham +1 · 1,395 citations
Physics and Astronomy · Social Sciences · #Astronomy and Astrophysical Research #Educational Leadership and Practices #Light curve #Limb darkening #Orbit (dynamics) #Planet #Planetary system #RADIUS #Radial velocity #Star (game theory) #Stellar, planetary, and galactic studies #Transit (satellite) #astro-ph
paper · pdf · doi:10.1086/312457
published in The Astrophysical Journal 529(1), L45-L48 (IOP Publishing) · 10 pages, 3 figures, accepted by ApJ Letters
arxiv created 1999/11/23 · openalex publication_date 2000/01/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We report high-precision, high-cadence photometric measurements of the star HD 209458, which is known from radial velocity measurements to have a planetary-mass companion in a close orbit. We detect two separate transit events at times that are consistent with the radial velocity measurements. In both cases, the detailed shape of the transit curve due to both the limb darkening of the star and the finite size of the planet is clearly evident. Assuming stellar parameters of 1.1 R middle dot in circle and 1.1 M middle dot in circle, we find that the data are best interpreted as a gas giant with a radius of 1.27+/-0.02 RJup in an orbit with an inclination of 87&fdg;1+/-0&fdg;2. We present values for the planetary surface gravity, escape velocity, and average density and discuss the numerous observations that are warranted now that a planet is known to transit the disk of its parent star.