A Study of the B Stars in the Orion Belt Region.

Abstract

Photoelectric UB V observations have been obtained for ninety-three B stars in the Orion Belt region. A comparison of these data with previous photometric studies is made in regard to possible systematic errors. An average distance modulus of 8.1 mag is found using a recent Scorpius calibration of B stars, but a systematic difference in this modulus amounting to about 0.9 mag. is present from the eastern to the western extremes of the Belt group. Various possible explanations of this difference are discussed. Thirty-eight fainter stars of later spectral type were also observed, but these observations do not add any information to the east-west systematic difference in distance modulus, and in fact these stars seem to have a modulus of 8.2 mag. regardless of their positions in the Belt region.