High Galactic latitude runaway stars

The initial sample is a collection of 174 early-type stars selected from the literature. The stars are first classified according to their evolutionary status in order to obtain a homogeneous sample of 96 genuine main-sequence stars.

Their present velocities and flight times are then estimated using proper motion data from various astrometric catalogues (including Tycho-2, UCAC2 and USNO-B) and the ejection velocities are computed by tracing their orbits back in time, based on a Galactic potential. The potential used is constructed from a mass density model chosen to fit the most recent observational constraints.