A test of B-type star Hβ photometric distances via the HIPPARCOS parallaxes

Abstract

We test the photometric uvbybeta distances for B III, IV and V type stars, with an emphasis on the effect of rotation on the M_V determination. From the M_V(uvbybeta ) calibration of Balona & Shobbrook (1984), we have derived the absolute visual magnitudes for 176 stars with v sin (i) measurements and have compared them to M_V values derived via the parallaxes, measured by Hipparcos. For the luminosity classes IV and V there is a good agreement between the photometric and trigonometric distances and no dependence on rotation. The photometric M_V values for luminosity class III show a tendency to be slightly larger than the corresponding Hipparcos determination. Probably this is due to the photometric calibration itself and it is not connected to the stellar rotation. Using the Hipparcos data, we also test the Crawford's (1978) M_V(beta ) reference line and the Philip & Egret (1980) and Schönberner & Harmanec (1995) M_V((b-y)_0) reference lines. The last one shows disagreement with the trigonometric luminosities at the bright star end. Based on data from the ESA Hipparcos astrometry satellite