A&A Supplement series, Vol. 122, April I 1997, 51-77
Received April 16; accepted June 26, 1996
, log g and [M/H]M. Künzli
- P. North
- R.L. Kurucz
- B. Nicolet
Send offprint request: M. Künzli
Institut d'Astronomie de l'Université de Lausanne,
CH-1290 Chavannes-des-Bois, Switzerland
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street,
Cambridge, Massachusetts 02138, U.S.A.
Observatoire de Genève, CH-1290 Sauverny, Switzerland
We have used recent Kurucz models and numerous standard stars to improve the
calibration of the Geneva photometric system proposed a few years ago.
A new photometric diagram for the classification of intermediate stars
(
) is proposed and fills
a gap that the previous calibration had left open.
Evidence is given for a clear inadequacy of the new Kurucz models in the
region of the parameter space where convection begins to take over radiation
in the star's atmosphere. This problem makes the determination of the surface
gravity difficult, but leaves that of the other parameters apparently
unaffected. The determination of metallicity is considerably improved,
thanks to the homogeneous spectroscopic data published recently by
Edvardsson et al. (1993).
Instead of showing the traditional diagrams, we chose to publish the diagrams
of the physical parameters with the inverted grids inside, i.e. the lines of
constant photometric parameters
keywords: stars: general; atmospheres; fundamental parameters