HIP 21539 is not a past very close neighbour of the Sun

Abstract

Aims. A previous study claimed that the star HIP 21539 passed close to the Sun, at a distance of 1.9 pc, around 0.14 Myr ago. We show that this is not the case. Methods. We redetermined the trajectory of the star relative to the Sun using a new accurate radial velocity from the HARPS spectrograph combined with the recent Gaia-TGAS astrometry. Results. With this new data, the closest approach of HIP 21539 to the Sun is now 17 pc, instead of 1.9 pc. Conclusions. At this distance, the star has not perturbed the Oort cloud.