A super-Earth orbiting the nearby M-dwarf GJ 536

TL;DR

This paper reports the discovery of a super-Earth exoplanet orbiting the nearby M-dwarf star GJ 536, using radial velocity data, and analyzes stellar activity signals to confirm planetary origin.

Contribution

First detection of a super-Earth around GJ 536 using HARPS data, with detailed analysis of stellar activity to confirm planetary signals.

Findings

GJ 536 b has a minimum mass of 5.36 Earth masses.

Orbital period of GJ 536 b is approximately 8.7 days.

Detected stellar rotation period at 43 days.

Abstract

We report the discovery of a super-Earth orbiting the star GJ 536 based on the analysis of the radial-velocity time series from the HARPS and HARPS-N spectrographs. GJ 536 b is a planet with a minimum mass M sin $i$ of 5.36 +- 0.69 Me with an orbital period of 8.7076 +- 0.0025 days at a distance of 0.066610(13) AU, and an orbit that is consistent with circular. The host star is the moderately quiet M1 V star GJ 536, located at 10 pc from the Sun. We find the presence of a second signal at 43 days that we relate to stellar rotation after analysing the time series of Ca II H&K and H alpha spectroscopic indicators and photometric data from the ASAS archive. We find no evidence linking the short period signal to any activity proxy. We also tentatively derived a stellar magnetic cycle of less than 3 years.