Spectrophotometric investigation of the spectroscopic binary system delta Orionis.
Abstract
The spectrum of the close binary Delta Ori is investigated using 77 spectrograms covering the spectral region from 6800 to 3650 A and obtained at different phases of the orbital period. Estimates of the component spectral types and the system's hydrogen-line luminosity indicate that the spectral type of the primary varies with orbital phase from O8.5 to O9.6, the spectral type of the secondary may be considered as B1, and the luminosity difference between the components is close to 2.5 magnitudes. The electron density, micro- and macroturbulence velocities, ionization temperature, and other physical parameters of the primary's atmosphere are determined. Based on a detailed study of the 5696-A C III line shape and a comparison with UV spectral data, it is concluded that Delta Ori has a greatly extended and strongly stratified atmosphere surrounded by an expanding circumstellar shell whose expansion velocity (mean value nearly 550 km/s) increases outwards.
- Publication:
-
Izvestiya Ordena Trudovogo Krasnogo Znameni Krymskoj Astrofizicheskoj Observatorii
- Pub Date:
- 1976
- Bibcode:
- 1976IzKry..54..128G
- Keywords:
-
- Binary Stars;
- Stellar Atmospheres;
- Stellar Spectrophotometry;
- Electron Density (Concentration);
- H Lines;
- Line Spectra;
- Stellar Envelopes;
- Stellar Magnitude;
- Temperature Distribution;
- Ubv Spectra;
- Astronomy