Copernicus ultraviolet observations of mass-loss effects in O and B stars

Far-UV spectra of 47 O, B, and A stars obtained with the Copernicus satellite are examined for P Cygni profiles. For all 40 stars with displaced absorption lines, values are given for the velocities of the short-wavelength edge, the line center, and the emission peak (if present). Parts of the spectra of 42 stars are reproduced, evidence for mass motions in ground-based spectra is discussed, and the best available data are summarized on the wavelengths and oscillator strengths of most lines likely to show mass-loss effects in either visual or UV spectra. The main conclusions are that: (1) the far-UV transitions, especially resonance lines, show that mass flow is present over a much wider group of stars than revealed by visible data on subordinate lines; (2) most of the line shifts imply mass motion away from the stars; (3) mass flow occurs in all but one star brighter than a bolometric magnitude of -6.0; and (4) the observed terminal velocities generally exhibit no significant correlation with temperature, luminosity, gravity, rotational velocity, or line strength.