Abstract

UB V colors and magnitudes are given for 251 stars in the region of the Scorpio-Centaurus association. Intrinsic colors and magnitudes corrected for interstellar absorption are computed by Johnson's Q method. The presence of strong differential reddening in a restricted area permitted an estimation of the ratio of total to selective absorption, whicb seems to be abnormally high for this zone. Absolute magnitudes were computed using moving cluster parallaxes. Luminosity calibration curves against both colors are given for all stars with known distance moduli. A study of the possible membership of the association is made for all program stars. H observations were made for all stars brighter than 6.5 which were retained as members or probable members from photometry; using Hardie and Crawford's calibration, new distance moduli were determined from the p values. The group has an elongated shape, making an angle of about 18 with the galactic plane.