An m sin i = 24 Earth Mass Planetary Companion To The Nearby M Dwarf GJ 176

TL;DR

This paper reports the discovery of a Neptune-mass planet orbiting the nearby M dwarf GJ 176, based on five years of high-precision radial velocity measurements, suggesting low-mass planets may be common around M dwarfs.

Contribution

First detection of a Neptune-mass planet around GJ 176 using long-term radial velocity data, expanding the known population of small planets around M dwarfs.

Findings

Planet has a minimum mass of 24.5 Earth masses.

Orbital period of the planet is 10.24 days.

Low-mass planets may be common around M dwarfs.

Abstract

We report the detection of a planetary companion with a minimum mass of m sin i = 0.0771 M_Jup = 24.5 M_Earth to the nearby (d = 9.4 pc) M2.5V star GJ 176. The star was observed as part of our M dwarf planet search at the Hobby-Eberly Telescope (HET). The detection is based on 5 years of high-precision differential radial velocity (RV) measurements using the High-Resolution-Spectrograph (HRS). The orbital period of the planet is 10.24 d. GJ 176 thus joins the small (but increasing) sample of M dwarfs hosting short-periodic planets with minimum masses in the Neptune-mass range. Low mass planets could be relatively common around M dwarfs and the current detections might represent the tip of a rocky planet population.