http://arxiv.org/abs/2209.12957
Aims. With an observing time span of more than 20 years, the CORALIE radial-velocity survey is able to detect long-term trends in data corresponding to companions with masses and separations accessible to direct imaging. Combining exoplanet detection techniques such as radial-velocities from the CORALIE survey, astrometric accelerations from Hipparcos and Gaia eDR3, and relative astrometry from direct imaging, removes the degeneracy of unknown orbital parameters. This allows precise model-independent masses of detected companions to be derived, which provides a powerful tool to test models of stellar and substellar mass-luminosity relations. Methods. Long-term precise Doppler measurements with the CORALIE spectrograph reveal radial-velocity signatures of companions on long-period orbits. The long baseline of radial-velocity data allows the detectability of such companion candidates to be assessed with direct imaging. We combine long-period radial-velocity data with absolute astrometry from Hipparcos and Gaia eDR3 and relative astrometry derived from new direct imaging detections with VLT/SPHERE to fit orbital parameters and derive precise dynamical masses of these companions. Results. In this paper we report the discovery of new companions orbiting HD~142234, HD~143616, and HIP~22059, as well as the first direct detection of HD~92987~B, and update the dynamical masses of two previously directly imaged companions; HD~157338~B and HD~195010~B. The companions span a period range of 32 to 273 years and are all very low mass stellar companions, ranging from 225 to 477~$M_{\rm{Jup}}$. We compare the derived dynamical masses to mass-luminosity relations of very low mass stars (<0.5~$M_{\odot}$), and discuss the importance of using precursor radial-velocity and astrometric information to inform the future of high-contrast imaging of exoplanets and brown dwarfs
E. Rickman, E. Matthews, W. Ceva, et. al.
Wed, 28 Sep 22
66/89
Comments: Accepted for publication in A&A