No CrossRef data available.
Published online by Cambridge University Press: 14 August 2015
We have obtained the observed fraction of supergiant (luminosity classes I and II), giant (III) and dwarf (IV-V) stars of spectral types B2 and earlier. The stellar sample used was formed with all the stars with bi-dimensional spectral classification listed in the Catalogue of Galactic O stars by Cruz-González et al. (1974), the unpublished compilation of B0 and B0.5 stars by J.F. Rayo, and the B1-B2 stars listed by Morgan et al. (1955). The latter sample is by far the least complete one. The results are listed in Table I, together with the total number of stars (in parenthesis) considered in each spectral interval. A prominent conclusion is drawn from the table: The fractions remain approximately constant all over the spectral range considered.