Astronomy Tea Talk

As the evolved descendants of massive stars and the progenitors of supernovae and compact objects, red supergiant stars act as a bridge between massive star evolution, astrophysical transients, and gravitational wave sources. One famous example is Betelgeuse, which unexpectedly became dimmer in 2019 but re-brightened in 2020, highlighting our poor understanding of these giant stars. Using a new implicit angle-dependent radiation transport module I developed in the moving-mesh code AREPO, I will explain how we can use AREPO - a code mostly used for cosmological simulations - to simulate realistic full-sphere 3D massive star envelope for the first time. I will highlight two scientific results: (1) multi-scale cooling-driven convection creating supergranulation reminiscent of solar convection, and (2) pulsation-lifted circumstellar material as an explanation for interacting supernovae. These results are only the starting point of the AREPO-Star project, aimed at simulating the multi-scale 3D physics of massive stars, binaries, and associated transients across the Hertzsprung-Russell diagram.