Effective temperatures, intrinsic colours, and surface gravities of yellow supergiants and cepheids.
Abstract
Effective temperatures, surface gravities, and colour excesses of supergiant stars in the spectral range F3-G3 are obtained by matching UVBGRI photometry with model atinosphere fluxes. Effective temperatures and surface brightnesses correlate very well with derived intrinsic B-V colours (UB V system) and confirm Kraft's widely-used Te - (B-V)0 relationship. Mean values of Te, (B-V)0, log g, and B.C. are given as functions of spectral class. There is very little overlap in the log g - Te plane between the pulsating and non-pulsating stars. Order-of-magnitude variations in surface gravity are found for many Cepheids which follow more closely the temperature and velocity variations than the dynamical accelerations of the atmospheres. Schwarzschild's running-wave hypothesis is revived in order to account for the behaviour of the effective surface gravity.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- 1971
- DOI:
- 10.1093/mnras/152.1.121
- Bibcode:
- 1971MNRAS.152..121P