Radio detection of the Be star psi Persei

The results of a VLA survey for radio emission from a sample of Be stars having strong excess emission in the IRAS bands are presented. Radio emission was detected from one star, ψ Persei. The radio flux density, together with nearly simultaneous ultraviolet and near-infrared observations, argue strongly against a spherically symmetric model for the circumstellar envelope, thus favouring equatorial disc models. In general it is found that the spectral index of the excess emission increases between the radio and far-infrared, suggesting either increased acceleration of the outflow at large distances from the star, partial recombination of the outer regions of the disc or divergence of the equatorial disc at large radii. (author)