Stellar model chromospheres. I. On the temperature minima of F,G, and K stars.
Abstract
Brightness temperatures are deduced for the Hiv and Kiv features of the Ca ii resonance lines in Procyon (F5 IV-V), Arcturus (K2 IlIp), and the Sun (G2 V). The brightness temperatures of Procyon and the Sun are in the same ratio as their effective temperatures, suggesting a simple scaling law for the temperature minima of F and early G stars. Arcturus departs from this law in a way that can be explained by CO line blanketing. Subject headings: Ca ii emission - chromosphere, solar chromospheres, stellar - late-type stars
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1973
- DOI:
- 10.1086/151977
- Bibcode:
- 1973ApJ...180..473L