The molecular envelope of the red supergiant VY CMa

Abstract

Millimeter and submillimeter interferometry allows to probe the environment around evolved massive stars, where optical and NIR studies might be severely limited by large extinctions due to dusty environments. We present here the morphology and kinematics of the molecular envelope around the red supergiant star VY CMa. We have used the Submillimeter Array (SMA) to map the 12CO(J=2-1) line and 1.3 mm continuum emissions with an unprecedent resolution of < 2" or 3000 AU. While the line emission presents a roughly circular shape with a radius of ∼ 6000 AU, the velocity structure is markedly different from that of a simple spherically expanding shell. In particular, there is a significant velocity gradient in the East-West direction, confirming the presence of a bipolar outflow. © 2006 International Astronomical Union.