A Planetary Mass Companion to the K0 Giant HD 17092

TL;DR

This paper reports the discovery of a planetary-mass companion orbiting the K0 giant HD 17092, providing insights into planet formation and evolution around intermediate-mass, post-main sequence stars.

Contribution

First detection of a planetary companion around a K0 giant star using radial velocity measurements, expanding knowledge of planetary systems around evolved stars.

Findings

Minimum planet mass of 4.6 Jupiter masses

Orbital semi-major axis of 1.3 AU

Eccentricity of 0.17

Abstract

We report the discovery of a substellar-mass companion to the K0-giant HD 17092 with the Hobby-Eberly Telescope. In the absence of any correlation of the observed 360-day periodicity with the standard indicators of stellar activity, the observed radial velocity variations are most plausibly explained in terms of a Keplerian motion of a planetary-mass body around the star. With the estimated stellar mass of 2.3Msun, the minimum mass of the planet is 4.6MJ. The planet's orbit is characterized by a mild eccentricity of e=0.17 and a semi-major axis of 1.3 AU. This is the tenth published detection of a planetary companion around a red giant star. Such discoveries add to our understanding of planet formation around intermediate-mass stars and they provide dynamical information on the evolution of planetary systems around post-main sequence stars.