EPIC247098361b: a transiting warm Saturn on an eccentric $P=11.2$ days orbit around a $V=9.9$ star

TL;DR

This paper reports the discovery and characterization of EPIC247098361b, a warm Saturn-sized exoplanet with an eccentric orbit around a bright star, providing valuable data for understanding giant planet formation and evolution.

Contribution

The paper presents the first detailed characterization of EPIC247098361b, including its mass, radius, orbit, and composition, based on combined Kepler K2 photometry and ground-based spectroscopy.

Findings

EPIC247098361b has a mass of 0.397 M_J and a radius of 1.00 R_J.

The planet orbits its star every 11.2 days with an eccentricity of 0.258.

The system's brightness makes it ideal for follow-up atmospheric and orbital studies.

Abstract

We report the discovery of EPIC247098361b using photometric data of the Kepler K2 satellite coupled with ground-based spectroscopic observations. EPIC247098361b has a mass of M$_{P}=0.397\pm 0.037$ M$_J$, a radius of R$_{P}=1.00 \pm 0.020$ R$_J$, and a moderately low equilibrium temperature of $T_{eq}=1030 \pm 15$ K due to its relatively large star-planet separation of $a=0.1036$ AU. EPIC247098361b orbits its bright ($V=9.9$) late F-type host star in an eccentric orbit ($e=0.258 \pm 0.025$) every 11.2 days, and is one of only four well characterized warm Jupiters having hosts stars brighter than $V=10$. We estimate a heavy element content of 20 $\pm$ 7 M$_{\oplus}$ for EPIC247098361b, which is consistent with standard models of giant planet formation. The bright host star of EPIC247098361b makes this system a well suited target for detailed follow-up observations that will aid in the study of the atmospheres and orbital evolution of giant planets at moderate separations from their host stars.