Line Broadening in High-Luminosity Stars. I. Bright Giants.

Line profiles have been obtained from high-dispersion spectra of a random sample of ten A- and F-type bright giants. These profiles match very well ones computed with the Doppler velocity from curves of growth combined with various amounts of rotation. The mean projected rotational velocity of 26 km/sec is in good agreement with that predicted from B stars and the Sandage-Schwarzschild evolutionary tracks, provided that the bright giants do not rotate as rigid bodies.