A Possible Substellar Companion to the Intermediate-mass Giant HD 175679

TL;DR

This paper reports the discovery of a substellar companion, likely a brown dwarf, orbiting the intermediate-mass giant HD 175679, based on precise radial velocity measurements indicating a Keplerian orbit.

Contribution

It presents the detection of a new substellar companion around an intermediate-mass giant, adding valuable data to the study of such objects and their formation.

Findings

Minimum mass of the companion is 37.3 ± 2.8 Jupiter masses.

Orbital period is approximately 1367 days.

Eccentricity of the orbit is 0.378.

Abstract

We report the discovery of a substellar companion around the intermediatemass giant HD 175679. Precise radial velocity data of the star from Xinglong Station and Okayama Astrophysical Observatory (OAO) revealed a Keplerian velocity variation with an orbital period of 1366.8 \pm 5.7 days, a semiamplitude of 380.2 \pm 3.2m s.1, and an eccentricity of 0.378 \pm 0.008. Adopting a stellar mass of 2.7 \pm 0.3 M\odot, we obtain the minimum mass of the HD 175679 b is 37.3 \pm 2.8 MJ, and the semimajor axis is 3.36 \pm 0.12 AU. This discovery is the second brown dwarf companion candidate from a joint planet-search program between China and Japan.