Mass loss from very luminous OB stars and the CYG superbubble.

Abstract

A description is presented of radio continuum measurements of mass loss from OB stars made at a wavelength of 6 cm with the Very Large Array (VLA). Five of the six most luminous members of the stellar association Cyg OB2 were detected. The considered investigation concentrates on the most luminous stars known in the Galaxy. The stars were selected because they would exhibit the most extreme consequences of mass loss and because they tend to be the brightest radio sources. The new mass loss rates are used to predict the properties of the interstellar bubble produced by the stellar winds of Cyg OB2. The results support the interpretation of Cash et al. (1980) that X-ray emission in the direction of Cygnus indicates a superbubble whose hot interior cavity contains the Cyg OB2 association.