* Astronomy

Title: HIP 21539 is not a past very close neighbour of the Sun
Author: F. Crifo, C. Soubiran, G. Jasniewicz, D. Katz, P. Sartoretti, P. Panuzzo

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.

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