Effects of Velocities on Ca II H and K Lines

Abstract

Ca II H and K (3968, 3933) and infrared triplet lines lamda lamda lamda 8498, 8662, 8542 were calculated in a very slowly expanding medium. Five level atom with continuum was considered. Radiative transfer equation and statistical equilibrium equations were solved simultaneously in the star's rest frame within the frame work of the discrete space theory technique of Grant and Peraiah (1972). Profiles were computed for the systematic expanding velocities 0.0, 0.5 and 1.0 (expressed in mean thermal units). Even though the velocities are small, they seem to effect the shape of the H and K profiles quite considerably. A single emission peak instead of a double peaked emission for the K lines was obtained when V = 1, and at mu = 0.79. These small velocities do not affect the infrared triplet lines significantly.