  The Galactic O star catalog (GOS) is an ambitious project to provide as much
information regarding these types of objects as possible. The first version of
the catalog (GOS v1) included data for 378 stars with precise spectral
classification. It was intended to be complete up to V < 8, but also included
many stars fainter than that limit. In this new version, we include a second
list with more than 700 stars that have sometimes been classified as O stars.
The catalog includes cross-references to other catalogs, spectral
classification (various references for each star on the second list),
coordinates (obtained in most cases from Tycho-2 data, but some from 2MASS and
USNO B1), astrometric distances for some of the nearer stars, Optical and NIR
photometry (Tycho-2, Johnson, Stromgren, Cousin and 2MASS), group membership,
runaway character, and multiplicity information.
