A survey of mass-loss effects in early-type stars.
Abstract
Intermediate-resolution data obtained with the Copernicus satellite are surveyed in order to define the region in the H-R diagram where mass loss occurs. The survey includes 40 stars, providing good coverage of supergiants from O4 to A2 and main-sequence stars from O4 to B7 as well as spotty coverage of late O giants and intermediate to late B stars. The spectral transitions examined are primarily resonance lines of ions of abundant elements plus some lines arising from excited states (e.g., C III at 1175.7 A and Si IV at 1122.5 A). Observed P Cygni profiles are discussed along with interesting features of some individual profiles. The data are shown to indicate that mass-loss effects occur over a wide portion of the H-R diagram, that mass ejection generally occurs when the holometric magnitude is greater than -6.0, and that the mass-ejection rate is usually high enough to produce P Cygni profile whenever the N V feature at 1240 A is present in a spectrum.
- Publication:
-
Stars and Galaxies from Observational Points of View
- Pub Date:
- 1976
- Bibcode:
- 1976sgov.meet..154S
- Keywords:
-
- Early Stars;
- Oao 3;
- Spaceborne Astronomy;
- Stellar Mass Ejection;
- B Stars;
- Hertzsprung-Russell Diagram;
- Main Sequence Stars;
- Stellar Spectra;
- Ultraviolet Spectra;
- Astrophysics