Angular Diameters of the G Subdwarf μ Cassiopeiae A and the K Dwarfs σ Draconis and HR 511 from Interferometric Measurements with the CHARA Array
Abstract
Using the longest baselines of the CHARA Array, we have measured the angular diameter of the G5 V subdwarf μ Cas A, the first such determination for a halo population star. We compare this result to new diameters for the higher metallicity K0 V stars, σ Dra and HR 511, and find that the metal-poor star, μ Cas A, has an effective temperature (Teff = 5297 +/- 32 K), radius (R = 0.791 +/- 0.008 R⊙), and absolute luminosity (L = 0.442 +/- 0.014 L⊙) comparable to those of the other two stars with later spectral types. We show that stellar models show a discrepancy in the predicted temperature and radius for μ Cas A, and we discuss these results and how they provide a key to understanding the fundamental relationships for stars with low metallicity.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2008
- DOI:
- 10.1086/589554
- arXiv:
- arXiv:0804.2719
- Bibcode:
- 2008ApJ...683..424B
- Keywords:
-
- infrared: stars;
- stars: fundamental parameters: temperatures diameters;
- stars: individual: HD 6582 HD 185144 HR 511 μ Cassiopeiae;
- subdwarfs;
- techniques: interferometric;
- Astrophysics
- E-Print:
- Accepted for publication in The Astrophysical Journal