Spectroscopic studies of O-type stars. VIII. Radial velocities and the K-term.
Abstract
Radial velocities are measured on coude spectrograms of over 200 O-type stars in both hemispheres. The selection of effective wavelengths for the stellar lines to be measured is reviewed, and the measured velocities are compared with those available in a catalog of O stars. The Trumpler (1935) effect (a reported anomalous redshift in certain O stars) is inconclusively reinvestigated, atmospheric motions in Of stars are examined, and some kinematic properties of O stars are discussed statistically. It is found that 58% of all O stars and 41% of all the Of stars considered are certain or probable binaries. A K-term in the range from 1 to 2 km/s is derived for the O stars, but the Of stars are shown to have a highly significant negative K-term. It is suggested that the systematically negative peculiar velocities of the Of stars are due to outflow of material beginning at the photospheric level.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1977
- DOI:
- 10.1086/155305
- Bibcode:
- 1977ApJ...214..759C
- Keywords:
-
- Binary Stars;
- Early Stars;
- O Stars;
- Radial Velocity;
- Red Shift;
- Stellar Mass Ejection;
- Computer Techniques;
- Line Spectra;
- Statistical Analysis;
- Stellar Motions;
- Stellar Spectra;
- Tables (Data);
- Astrophysics