Radio Photosphere and Mass‐Loss Envelope of VY Canis Majoris

Abstract

We have used the VLA to detect emission from the supergiant VY CMa atradio wavelengths and have constructed 3000-4500 K isothermal outeratmospheres constrained by the data. These models produce a radiophotosphere at 1.5-2 R_{*}. An extrapolation of the model canaccount for the observed total mass-loss rate of the star. We alsopresent mid-infrared imaging of the supergiant which suggests that warmdust is extended in the same direction as the near-infrared reflectionnebula around VY CMa. The origin of the asymmetries in the outflowremains an unsolved problem.