A general method of estimating stellar astrophysical parameters from photometry

Context. Applying photometric catalogs to the study of the population of the Galaxy is obscured by the impossibility to map directly photometric colors into astrophysical parameters. Most of all-sky catalogs like ASCC or 2MASS are based upon broad-band photometric systems, and the use of broad photometric bands complicates the determination of the astrophysical parameters for individual stars. Aims. This paper presents an algorithm for determining stellar astrophysical parameters (effective temperature, gravity and metallicity) from broad-band photometry even in the presence of interstellar reddening. This method suits the combination of narrow bands as well. Methods. We applied the method of interval-cluster analysis to finding stellar astrophysical parameters based on the newest Kurucz models calibrated with the use of a compiled catalog of stellar parameters. Results. Our new method of determining astrophysical parameters allows all possible solutions to be located in the effective temperature-gravity-metallicity space for the star and selection of the most probable solution.