An interpretation of the spectral variations of theta Coronae Borealis.

Abstract

Measurements are presented of the strengths and displacements of sharp absorption components of the resonance lines of Si IV, C IV, and Al III in the spectrum of θ CrB. No evidence is found for mass loss at a detectable rate. A qualitative model of a Be star is developed. It is suggested that the spectral variations of θ CrB are the result of changes in the rate at which magnetic flux is generated in the envelope of the star and extruded through the photosphere of the star.