Kepler-14b: A massive hot Jupiter transiting an F star in a close visual binary

TL;DR

This paper reports the discovery of Kepler-14b, a hot Jupiter in a binary system, emphasizing the importance of high-resolution imaging to accurately determine planetary parameters affected by stellar companion dilution.

Contribution

It highlights the impact of unresolved stellar companions on exoplanet parameter estimation and provides corrected measurements for Kepler-14b.

Findings

Unresolved stellar companions can cause significant underestimation of exoplanet sizes and masses.

High-resolution imaging is crucial for accurate exoplanet characterization.

Kepler-14b has a mass of approximately 8.4 Jupiter masses and a radius of about 1.14 Jupiter radii.

Abstract

We present the discovery of a hot Jupiter transiting an F star in a close visual (0.3" sky projected angular separation) binary system. The dilution of the host star's light by the nearly equal magnitude stellar companion (~ 0.5 magnitudes fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10% and 60%, respectively. Other published exoplanets, which have not been observed with high-resolution imaging, could similarly have unresolved stellar companions and thus have incorrectly derived planetary parameters. Kepler-14b (KOI-98) has a period of P = 6.790 days and correcting for the dilution, has a mass of Mp = 8.40 +0.19-0.18 MJ and a radius of Rp = 1.136 +0.073-0.054 RJ, yielding a mean density of rho = 7.1 +- 1.1 g cm-3.