Functional relationships for T_eff and log g in F-G supergiants from uvby-beta photometry
Abstract
From photoelectric uvby-beta data and recent accurate synthetic and spectroscopic values of T_eff and log g for 50 F-G supergiants, we have calculated functional relationships that lead to initial estimates of effective temperature and gravities for these types of stars. It is shown that while the T_eff relationships are calculated using the data on young massive supergiants, they are also valid for evolved stars of similar temperatures like post-AGB and RV Tau stars. The gravity can also be predicted from the Delta [c_1] index with an uncertainty of about 0.26 dex. Although a clear and significant trend between M_V and Delta [c_1] is seen, no calibration is found that predicts accurate values of M_V.
- Publication:
-
Revista Mexicana de Astronomia y Astrofisica
- Pub Date:
- October 2010
- DOI:
- 10.48550/arXiv.1007.0771
- arXiv:
- arXiv:1007.0771
- Bibcode:
- 2010RMxAA..46..331A
- Keywords:
-
- stars: AGB and post-AGB;
- supergiants;
- techniques: photometric;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- To be published Octuber 2010. 8 pages, 7 figures, 2 tables