Astron. Astrophys. Suppl. Ser.
Volume 142, Number 3, March II 2000
|Page(s)||389 - 398|
|Published online||15 March 2000|
Spectral classification of O–M stars on the basis of UBV photometry
International Centre for Astronomical, Medical and Ecological Investigations, National Academy of Sciencies of the Ukraine, Golosiiv, 252680 Kyiv-127, Ukraine e-mail: firstname.lastname@example.org
2 Main Astronomical Observatory, National Academy of Sciencies of the Ukraine, Golosiiv, 252680 Kyiv-127, Ukraine e-mail: email@example.com
Send offprint request to: V.I. Kuznetsov
Accepted: 29 November 1999
A new technique allowing the Q-method to be used surely for both the spectral classification of young O–A0 stars and older spectral subclasses A1–M5 is described. Characteristics of interstellar light absorption dependence on distance in the given direction of the sky is used as a main criterion for excluding possible multiplicity of star spectral estimates at some constant values of QUBV. Information on open cluster membership probabilities is also useful as additional criterion of the spectral classification. The method was tested on stars up to mag in directions of young open clusters NGC 2244 and NGC 2264. The spectral study based on UBV photometry was extended to faint stars of NGC 2264 in the V magnitude range 17-22 mag.
Key words: methods: numerical / stars: fundamental parameters / ISM: dust, extinction / Galaxy: open clusters and associations: individual: NGC 2244; NGC 2264
© European Southern Observatory (ESO), 2000