Multi techniques approach to identify and/or constrain radial velocity sub-stellar companions

TL;DR

This study combines radial velocity, astrometry, and proper motion anomaly analysis to discover and characterize new sub-stellar companions, including planets and brown dwarfs, using archival ESO/HARPS data.

Contribution

It introduces a multi-technique approach integrating RV, astrometry, and proper motion anomalies to detect and characterize sub-stellar companions in archival data.

Findings

Discovered and characterized 3 brown dwarfs and 6 planets.

Constrained orbital inclinations and true masses of known companions.

Identified 12 new stellar companions.

Abstract

Context. Although more than one thousand sub-stellar companions have already been detected with the radial velocity (RV) method, many new companions remain to be detected in the public RV archives. Aims. We wish to use the archival data obtained with the ESO/HARPS spectrograph to search for sub-stellar companions. Methods. We use the astronomic acceleration measurements of stars obtained with the Hipparcos and Gaia satellites to identify anomalies that could be explained by the presence of a companion. Once hints for a companion are found, we combine the RV data with absolute astrometry and, when available, relative astrometry data, using a Markov Chain Monte Carlo (MCMC) algorithm to determine the orbital parameters and mass of the companion. Results. We find and characterize three new brown dwarfs (GJ660.1 C, HD73256 B, and HD165131 B) and six new planets (HD75302 b, HD108202 b, HD135625 b, HD185283 b, HIP10337 b, and HIP54597 b) with separations between 1 and 6 au and masses between 0.6 and 100 MJup. We also constrain the orbital inclination of ten known sub-stellar companions and determine their true mass. Finally, we identify twelve new stellar companions. This shows that the analysis of proper motion anomalies allows for optimizing the RV search for sub-stellar companions and their characterization.