Left Ringing: Betelgeuse Illuminates the Connection Between Convective outbursts, Mode switching, and Mass Ejection in Red Supergiants

Understand

Betelgeuse, the nearest red supergiant, dimmed to an unprecedented level in early 2020.

• The star emerged from this Great Dimming episode with its typical, roughly 400-day pulsation cycle halved, and a new dominant period of around 200 days.
• The dimming event has been attributed to a surface mass ejection, in which rising material drove shocks through the stellar atmosphere and expelled some material, partially obscuring the star as it formed molecules and dust.
• In this paper, we use hydrodynamic simulations to reveal the connections between Betelgeuse's vigorously convective envelope, the surface mass ejection, and the pulsation mode switching that ensued.