Dust-forming molecules in VY Canis Majoris (and Betelgeuse)

TL;DR

This paper investigates the formation of dust in evolved stars by analyzing molecules like AlO, TiO, and TiO2 in VY CMa, suggesting non-equilibrium chemistry plays a key role, and explores their potential presence in Betelgeuse.

Contribution

It provides new observational evidence of dust-forming molecules in VY CMa and discusses their possible detection in Betelgeuse's environment.

Findings

Detection of AlO, TiO, and TiO2 in VY CMa

Evidence for non-equilibrium chemistry in dust formation

Discussion of molecular presence in Betelgeuse

Abstract

The formation of inorganic dust in circumstellar environments of evolved stars is poorly understood. Spectra of molecules thought to be most important for the nucleation, i.e. AlO, TiO, and TiO2, have been recently detected in the red supergiant VY CMa. These molecules are effectively formed in VY CMa and the observations suggest that non-equilibrium chemistry must be involved in their formation and nucleation into dust. In addition to exploring the recent observations of VY CMa, we briefly discuss the possibility of detecting these molecules in the dust-poor circumstellar environment of Betelgeuse.