Rocket-ultraviolet spectra of kappa, lambda, tau, and upsilon Scorpii

The present work describes high- and low-resolution rocket-ultraviolet spectra of kappa, lambda, tau, and upsilon Scorpii obtained in the range from 1160 to 1880 A. The Si IV resonance lines in tau Sco show asymmetries indicating outward mass motions of up to about 400 km/sec. The suitability of some of the lines observed for indication of luminosity or temperature is discussed. It is pointed out that the intrinsic strength and large changes of the lines of Si III and C IV may permit a more accurate spectral classification of stars between B0 and B3 than has been demonstrated in this same spectral type region using visible spectra.