On the ionization equilibrium in late-type supergiants.
Abstract
We have studied the ionization balance in late-type supergiants of spectral types G5 to M2 using the Ca I 6573 A and forbidden Ca I 7324 A lines as a probe. An increasing discrepancy is found between the observed and calculated line strengths setting in for an effective temperature less than approximately 4250 K. This is interpreted in terms of increased ionization relative to local thermodynamic equilibrium.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1981
- DOI:
- 10.1086/158874
- Bibcode:
- 1981ApJ...245..984R
- Keywords:
-
- Ionization;
- Late Stars;
- Stellar Models;
- Stellar Spectra;
- Supergiant Stars;
- Thermodynamic Equilibrium;
- Computer Graphics;
- Computerized Simulation;
- Line Spectra;
- M Stars;
- Stellar Atmospheres;
- Stellar Evolution;
- Stellar Temperature;
- Astrophysics