We report the direct detection of a fully convective , early-to-mid M-dwarf companion orbiting the star HD 86006 , using ESO-SPHERE during Science Verification as part of the SAFARI program .
HARPS+CORALIE radial velocity measurements first indicated a possible companion .
Such work highlights the synergies that are now possible between these two observing methods .
We studied the companion by comparing our observed spectra with BT-Settl models and template spectra , measuring spectral indices to obtain a spectral type , and used a joint radial velocity and astrometric fit to simulate the companion ’ s orbit .
The companion was found to be 4.14 mag fainter than the primary in the H2 band , residing at a physical separation of \sim 25 AU , with a T _ { \mathrm { eff } } and spectral type of 3321 \pm 111 K and M 4.1 \pm 1.1 , respectively .
We note that the age derived from BT-Settl models for such a star is too low by over two orders of magnitude , similar to other known field mid-M stars .
We searched for the radial velocity companion to HD 90520 without any clear detection , however we reached a low contrast level of \Delta H2 = 10.3 mag ( or 1.3 * 10 ^ { -4 } ) at 0.2 ^ { \prime \prime } and 12.6 mag ( or 10 ^ { -5 } ) at 0.5 ^ { \prime \prime } , allowing us to rule out any low-mass companions with masses of 0.07 and 0.05 M _ { \odot } at these separations .
This discovery provides us with the exciting opportunity to better constrain the mass-luminosity relation for low-mass stars in the super metal-rich domain , expanding our understanding of the most-common types of stars and substellar objects .