Astron. Astrophys. Suppl. Ser.
Volume 140, Number 3, December II 1999
|Page(s)||261 - 277|
|Published online||15 December 1999|
The effective temperature scale of giant stars (F0–K5)
II. Empirical calibration of versus colours and [Fe/H]
Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
Send offprint request to: A. Alonso
Accepted: 23 July 1999
We present calibrations of the effective temperatures of giant stars versus [Fe/H] and colours , , , , , , , , , , and . These calibrations are based on a large sample of field and globular cluster stars which roughly cover spectral types from F0 to K5. Their effective temperatures, scaled to direct determinations via reliable angular diameter measurements, were derived by applying the infrared flux method. The empirical relations have been fitted to polynomials of the form by using the least squares method. The precision of the fits ranges from 40 K for to 170 K for . We tabulate intrinsic colours of giant stars in the ranges: 3500 K 8000 K; -3.0 . We also present the calibration of BC(V) as a function of log and metallicity. Finally, we compare the resulting scale of temperatures with previous works.
Key words: stars: fundamental parameters / stars: Population II / stars: giants / stars: atmospheres / stars: general
© European Southern Observatory (ESO), 1999