A substellar component orbiting the F-star 30 Ari B

TL;DR

This paper reports the discovery of a substellar companion to the F-star 30 Ari B, detected via radial velocity measurements, with a mass near the planet-brown dwarf boundary, contributing to understanding of such companions around more massive stars.

Contribution

First detection of a substellar companion orbiting a more massive F-star, expanding knowledge of giant planet and brown dwarf occurrence around such stars.

Findings

Companion has a period of 335 days and eccentricity of 0.289.

Mass of the companion is approximately 9.88 Jupiter masses.

The object is classified as either a massive planet or brown dwarf.

Abstract

CONTEXT: Most current radial velocity planet search programs have concentrated on stars of one solar mass. Our knowledge on the frequency of giant planets and brown dwarf companions to more massive stars is thus rather limited. In the case of solar-like stars, the frequency of short-period brown dwarf companions and very massive planets seems to be low. AIMS: Here we present evidence for a substellar companion to 30 Ari B, an F-star of 1.16 $\pm$ 0.04 $\rm M_\odot$ that is a member of a hierarchical triple system. METHODS: The companion was detected by means of precise radial velocity measurements using the 2-m Alfred-Jensch telescope and its 'echelle spectrograph. An iodine absorption cell provided the wavelength reference for precise stellar radial velocity measurements. RESULTS: We analyzed our radial velocity measurements and derived an orbit to the companion with period, P= 335.1+/-2.5 days, eccentricity e = 0.289+/-0.092, and mass function f(m) = (6.1+/-1.7)*10E-7 Modot. CONCLUSIONS: We conclude that the radial velocity variations of 30 Ari B are due to a companion with $m$ sin $i$ of $9.88\pm0.94$ $\rm M_{Jup}$ that is either a massive planet or a brown dwarf. {The object thus belongs to the rare class of massive planets and brown dwarfs orbiting main- sequence stars.