On the Initial Mass Function of Be Stars and the Missing Be Stars of Late Spectral Types

Abstract

AbstractThis is an attempt at determining the IMF (Initial Mass Function) of Be stars relative to that of B stars in the vicinity of the Sun. We have represented the IMF as a power function of the stellar mass Mβ, so that the relative IMF is then proportional to Mβ(Be)–β(B). Allowing for systematic differences in the counting of Be stars due to their apparent overluminosity, a difference β(Be) – β(B) ~ 0 is found, which may indicate that there are no huge intrinsic differences between the two types of objects. In these calculations changes of spectral types due to high rotation were not taken into account. This effect may still strongly affect the results obtained. By extrapolating the MβBe) – β(B) curve to spectral types later than B7, we reckon that in a volume limited to the apparent magnitude V = 7 there may be about 150 still undetected Be stars of late spectral types.