Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes

作者：Stassun, Keivan G.^*; Collins, Karen A.; Gaudi, B. Scott

来源：Astronomical Journal, 2017, 153(3): 136.

DOI：10.3847/1538-3881/aa5df3

• astronomical databases: miscellaneous
• methods: data analysis
• planets and satellites: fundamental parameters
• stars: fundamental parameters

We present empirical measurements of the radii of 116 stars that host transiting planets. These radii are determined using only direct observables-the bolometric flux at Earth, the effective temperature, and the parallax provided by the Gaia first data release-and thus are virtually model independent, with extinction being the only free parameter. We also determine each star's mass using our newly determined radius and the stellar density, a virtually model independent quantity itself from previously published transit analyses. These stellar radii and masses are in turn used to redetermine the transiting-planet radii and masses, again using only direct observables. The median uncertainties on the stellar radii and masses are 8% and 30%, respectively, and the resulting uncertainties on the planet radii and masses are 9% and 22%, respectively. These accuracies are generally larger than previously published model-dependent precisions of 5% and 6% on the planet radii and masses, respectively, but the newly determined values are purely empirical. We additionally report radii for 242 stars hosting radialvelocity (non-transiting) planets, with a median achieved accuracy of approximate to 2%. Using our empirical stellar masses we verify that the majority of putative "retired A stars" in the sample are indeed more massive than similar to 1.2. M-circle dot. Most importantly, the bolometric fluxes and angular radii reported here for a total of 498 planet host stars-with median accuracies of 1.7% and 1.8%, respectively-serve as a fundamental data set to permit the re-determination of transiting-planet radii and masses with the Gaia second data release to approximate to 3% and approximate to 5% accuracy, better than currently published precisions, and determined in an entirely empirical fashion.

• 出版日期2017-3