Deep photospheric flows in tau Scorpii.
Abstract
From analysis of weak, unblended, ultraviolet lines observed in Tau Scorpii by Copernicus, the same line widths and the same slightly blue-depressed wings as found in the upper photospheric lines of the visual region are found. In addition, a radial-velocity discrepancy of about 6 km/s between weak and strong lines in the 1000-1300-A region is found. These results are in quantitative agreement with one another and with the results of the visual region. They imply that a flow of material is present even in the deep photosphere of this star. However, one cannot yet specify the geometry of the flow (outward-radial versus temperature-weighted convection columns). At the least, this flow alters the expected radiation-driven flow solution close to the photosphere. At the most, it could provide the heating of a chromosphere or a corona just outside the photosphere, as required by the imperfect flow model.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1979
- DOI:
- 10.1086/157071
- Bibcode:
- 1979ApJ...230..156S
- Keywords:
-
- B Stars;
- Photosphere;
- Stellar Atmospheres;
- Stellar Mass Ejection;
- Stellar Winds;
- Ultraviolet Spectra;
- Chromosphere;
- Convective Heat Transfer;
- Flow Velocity;
- Frequency Shift;
- Hot Stars;
- Line Spectra;
- Mass Transfer;
- Oao 3;
- Radial Velocity;
- Stellar Coronas;
- Astrophysics;
- Early-Type Stars:Line Profiles;
- Early-Type Stars:Stellar Winds;
- Early-Type Stars:UV Spectra