VY CMa

Book chapter, 2023

VY Canis Majoris is a massive, red, supergiant star, which is evolving toward a supernova explosion. It is currently in a state characterized by substantial mass loss from its surface, which creates a dense circumstellar envelope, with a complicated morphology, which is rich in primarily oxygen-bearing species and cosmic dust (most likely in the form of silicates). The oxygen-rich nature of its circumstellar matter (i.e., the abundance of oxygen is higher than that of carbon) limits somewhat the chemical complexity, but more than 20 circumstellar molecular species have been detected. Noteworthy is the presence of aluminum, phosphorus, and titanium oxides.