HIP 60350: an extreme runaway star

Abstract

Using Hipparcos proper motion as well as published and our own radial velocity data we identify HIP 60350 as fastest young B-type runaway star ejected 20 Myr ago or slightly less from the galactic plane, probably at a distance from the galactic center corresponding to spiral arm -II. Both the LSR velocity (417 kms(-1) ) and the mass of the star point to dynamical cluster ejection rather than to a supernova scenario. Published and our own photometric data as well as our spectroscopic evidence reveal no noticeable peculiarity and a spectral type B4/5 V. No significant radial velocity variations have been found during the last two decades. Based on data obtained with the Multiple Mirror Telescope, a joint facility of the University of Arizona and the Smithsonian Institution and from the ESA Hipparcos astrometry satellite