2025/08/13 by Matthew A. Kenworthy, Matthew Kenworthy, T. Stolker +41 · 2 voices · 2 citations
Physics and Astronomy · Chemistry · #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies #Spectroscopy and Laser Applications
paper · pdf · doi:10.1051/0004-6361/202556170
Aims . We wish to confirm the nature of YSES 2b, a purportedly faint companion of the young star YSES 2. Methods . We used on-sky observations from SPHERE and GRAVITY to measure the astrometric position of 2b with respect to the star YSES 2, and examined the competing hypotheses of (i) a bound substellar companion versus (ii) a distant unrelated background source with a non-zero proper motion. Results . YSES 2b appears to be a late-type M-dwarf star over 2 kiloparsecs behind the star YSES 2. It has a transverse velocity of ∼300 km s −1 and is located within one of the spiral arms of the Galaxy. The main discriminant was multiple epochs of GRAVITY astrometry that identified the sub-milliarcsecond parallactic motion of the star.