When Cannibal Stars Shine: How Common Envelope (Binary Star) Evolution May Be Observable with the Vera C. Rubin Telescope

Toward the end of a star's life, it can expand to over 100-times its original size, engulfing everything nearby. If that star was born with a lower-mass companion star, the companion may get cannibalized by the growing star. What happens next is a rapid mess of energy and angular momentum transfer that may be observable with the new Vera Rubin telescope in Chile. The process of stellar cannibalization, also known as Common Envelope Evolution, is an area of active research as the exact energy and momentum transfer mechanisms are still not well understood. Convection in the envelope of the expanded star may play a large role, and would contribute to the observability of this fleeting (<100 years) phenomenon. The newly on-line Vera C. Rubin telescope may be able to catch stellar cannibalization in-the-act, providing limits on the effect of convection during common envelope evolution.