Independent validation of the temperate Super-Earth HD79211 b using HARPS-N

TL;DR

This study confirms the existence of a Super-Earth around HD79211 using high-precision radial velocity measurements from HARPS-N, refining its parameters and contributing to understanding planet formation in binary systems.

Contribution

It provides the first independent validation of the HD79211 b planet candidate with HARPS-N data and refines its orbital and mass parameters using 25 years of combined RV data.

Findings

Confirmed the planet candidate with HARPS-N RVs.

Refined the planet's orbital period to 24.422 days.

No additional planets detected in the system.

Abstract

We present high-precision radial velocities (RVs) from the HARPS-N spectrograph for HD79210 and HD79211, two M0V members of a gravitationally-bound binary system. We detect a planet candidate with a period of $24.421^{+0.016}_{-0.017}$ days around HD79211 in these HARPS-N RVs, validating the planet candidate originally identified in CARMENES RV data alone. Using HARPS-N, CARMENES and HIRES RVs spanning a total of 25 years, we further refine the planet candidate parameters to $P=24.422\pm0.014$ days, $K=3.19\pm0.27$ m/s, $M$ sin $i = 10.6 \pm 1.2 M_\oplus$, and $a = 0.142 \pm0.005$ au. We do not find any additional planet candidate signals in the data of HD79211 nor do we find any planet candidate signals in HD79210. This system adds to the number of exoplanets detected in binaries with M dwarf members, and serves as a case study for planet formation in stellar binaries.