DRAFT
Caltech Logo

TAPIR Seminar

Friday, May 6, 2022
2:00pm to 3:00pm
Add to Cal
Cahill 370
Death Stars: Ring explosions from flattened stars
Marcus DuPont, Graduate Student, Theoretical Physics, New York University,

In person and online -- to Join via Zoom

https://caltech.zoom.us/j/89695722750

The stellar cataclysms producing astronomical transients have long been modeled as either a point-like explosion or jet-like engine ignited at the center of a spherically symmetric star. However, many stars are observed, or are expected on theoretical grounds, not to be precisely spherically symmetric, but rather to have a slightly flattened geometry similar to that of an oblate spheroid. Here we present axisymmetric two-dimensional hydrodynamical simulations of the dynamics of point-like explosions initiated at the center of an aspherical massive star with a range of oblateness. We refer to these exploding aspherical stars as "ellipsars" in reference to the elliptical shape of the iso-density contours of their progenitors in the two-dimensional axisymmetric case. We find that ellipsars are capable of accelerating expanding rings of relativistic ejecta which may lead to the production of astronomical transients including low-luminosity GRBs, relativistic supernovae, and Fast Blue Optical Transients (FBOTs.)

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at [email protected].