Vilnius Paper Abstracts

Straizys V., et al. (1993, Baltic Astr. 2, 326)


Colour indices and reddening-free Q-parameters in the Vilnius photometric system of B-type stars of all luminosities and A-supergiants are calibrated in terms of effective temperature and surface gravity, using synthetic spectra of the newest Kurucz model atmospheres. The calibration is verified by comparing the photometrically determined effective temperatures and surfaces gravities with the most accurate spectroscopic data. Satisfactory agreement has been found, proving the accuray of the calibration within +0.02 to +0.05 dex in log Te and +0.2 to +0.3 dex in log g.

Tautvaisiene G., Lazauskaite R. (1993, Baltic Astr. 2, 256)


A new semi-empirical surface gravity calibration of the intrinsic colour indices U-P and U-X of the Vilnius photometric system is presented. It is applicable for giants of all metallicities with temperatures from 4200K to 5500K and log g from 0.5 dex to 3.0 dex. The standard deviation of the observed minus predicted log g residuals is about +0.3dex. The U-P colour index is found to be a very good surface gravity indicator, and it can be used for for log g determination even when other atmospheric parameters (temperature and metallicity) are poorly known. The main atmospheric parameters for 93 red metal-deficient giants are determined from colour indices of the Vilnius system and compared with the evolutionary isochrones.

Lazauskaite R. (1995, Baltic Astr. 4, 48)


Calibrations giving Mv as function of [Fe/H] and various intrinsic color indices of the Vilnius photometric system are derived for G-K dwarfs and subdwarfs. The calibration are based only on the stars with known trigonometric parallaxes and allow one to estimate the absolute magnitudes with a standard deviation of +-0.6 mag. Comparisons of our calibrations with the absolute magnitude estimates in the literature show a satisfactory agreement.
Last update: 7 Novembre 1995