text: 492,76,1440222180550197249,204261944,Matthew Kenworthy,"New paper day! @ajbohn discusses ""Unveiling wide-orbit companions to K-type stars in Sco-Cen with Gaia EDR3"" <LINK> where he selected common proper motion companions (including stars from the YSES survey that has discovered 3 directly imaged exoplanets) /1 <LINK> @ajbohn Alex noted that one of the brown dwarfs detected in the YSES survey was bright enough to be detected in the GAIA catalogue - which made us wonder about more distant comoving companions, so he searched and found many more! The astrometric precision of GAIA enabled us to test /2 <LINK> @ajbohn whether they were bound by comparing the projected velocity between the star and the candidate companion with the maximum bound velocity, enabling us to reject unbound companions. The GAIA photometry also allowed us to estimate the mass of the companions too. /3 <LINK> @ajbohn Looking at 480 K-type stars, there are 163 potential companions to 142 stars including 21 candidate triple systems, and about a dozen brown dwarf candidates. One BD was seen by SPHERE and Gaia, and the SED from SPHERE agrees with the GAIA photometric mass estimate. /4 <LINK> @ajbohn It was great to see this paper get accepted before @ajbohn's thesis defence tomorrow, and I'm very proud of all of Alex's work on this and the other papers.",https://arxiv.org/abs/2109.09185,"Abbreviated. We aim to identify new low-mass companions to young stars using the astrometric measurements provided by the Gaia space mission and complementary VLT/SPHERE data. We identify companion candidates from a sample of K-type, pre-main sequence stars in the Scorpius Centaurus association using the early version of the third data release of the Gaia space mission. Based on the provided positions, proper motions, and magnitudes, we identify all objects within a predefined radius whose differential proper motions are consistent with a gravitationally bound system. We derive companion masses through comparison with evolutionary tracks. For seven identified companion candidates we use additional data collected with VLT/SPHERE and VLT/NACO to assess the accuracy of the properties of the companions based on Gaia photometry alone. We identify 110 comoving companions that have a companionship likelihood of more than $95\,\%$. We identify ten especially intriguing companions that have masses in the brown dwarf regime down to $20\,M_\mathrm{Jup}$. Our high-contrast imaging data confirm both astrometry and photometric masses derived from Gaia alone. We discover a new brown dwarf companion, TYC 8252-533-1 B, with a projected separation of approximately $570\,\mathrm{au}$ from its Sun-like primary. SED modeling provides a companion mass of $52^{+17}_{-11}\,M_\mathrm{Jup}$. We show that the Gaia database can identify low-mass companions at wide separations from their host stars. For K-type Sco-Cen members Gaia can detect sub-stellar objects at projected separations larger than $300\,\mathrm{au}$ and is sensitivity limited beyond $1,000\,\mathrm{au}$ with a lower mass limit down to $20\,M_\mathrm{Jup}$. A similar analysis of other star-forming regions could significantly enlarge the sample size of such objects and test formation and evolution theories of planetary systems. ","Unveiling wide-orbit companions to K-type stars in Sco-Cen with Gaia