Short time changes in the terminal velocity of the stellar wind of alpha Cam ((O9.5 Ia).
Macchetto, F.; Lamers, H. J. G. L. M.; de Jager, C.; Snow, T. P.
Netherlands, United States
Abstract
The UV spectrum of the star Alpha Cam (09.5 Ia) was observed for 72 hours continuously in September 1978, with IUE. During these three days the star shows gradual short-term changes of the edge velocity of the C IV and N V resonance lines. The change is largest for the lines formed at large distance from the star, and may be due to either UV-flux variations of the star or variations in the mass loss rate (puffs). Evidence is also found for erratic very-short terms variations of the edge velocities. These are probably correlated with the ionization equilibrium: the ions with the highest ionization potential showing the largest variations.