On the Spectra and Temperatures of the B Stars

Abstract

THE application of the theory of ionisation to stellar spectra by Saha and others has led to estimates of the temperature of the reversing layers of stars. It is shown by Fowler and Milne (Mon. Not. R.A.S., 83, 7, 415) that the effective temperature at a given point in the stellar sequence may be deduced, on certain assumptions, from the knowledge that a line of known series relations there reaches its maximum intensity. For stars of type earlier than Ao the lines available for such estimates are those associated with Si⁺⁺⁺, He, and C⁺. The intensities of these lines have recently been measured on a number of objective prism spectra at the Harvard College Observatory.