THE DISTRIBUTION OF ROTATIONAL VELOCITY FOR EVOLVED STARS

In this work we present the distribution of the projected rotational v elocity Vsini for evolved stars of luminosity classes IV, III and II. Such distribution is studied as a function of the color index and the spectral type for a large sample of about 1600 stars, with spectral ty pes ranging from middle F to middle K, complete to magnitude 6.5. We s how essentially that F giant stars present a broad distribution of Vsi ni values, whereas G and K giants present strikingly similar distribut ions reaching a maximum at very low values and decreasing abruptly wit h increasing Vsini values. The mean rotational velocity is given as a function of the color index and spectral type.