Ellipsars: Ring-like explosions from flattened stars

Abstract

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.)

Edit: Update to remove typo introduced in the revision on version 2

References in corpus (16)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Binary interaction dominates the evolution of massive stars
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Supernova -- Gamma-Ray Burst Connection
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Theory of Core-Collapse Supernovae
• Rapidly-Evolving and Luminous Transients from Pan-STARRS1
• CMasher: Scientific colormaps for making accessible, informative and 'cmashing' plots
• Magnetorotational Core-Collapse Supernovae in Three Dimensions
• Low-Luminosity Gamma-Ray Bursts as a Distinct GRB Population:A Firmer Case from Multiple Criteria Constraints
• High-energy Cosmic Rays and Neutrinos from Semi-relativistic Hypernovae
• On the Determination of the Rotational Oblateness of Achernar
• Shocked jets in CCSNe can power the zoo of fast blue optical transients
• A common envelope jets supernova (CEJSN) impostor scenario for fast blue optical transients
• Bolometric light curves of aspherical shock breakout
• Oblique Shock Breakout in Supernovae and Gamma-Ray Bursts: II. Numerical Solutions For Non-Relativistic Pattern Speeds

Cited by in corpus (3)

• Multi-wavelength observations of the Luminous Fast Blue Optical Transient AT2023fhn
• Observability of flashes from ejecta crashes in aspherical supernovae, with application to SN 2008D
• Luminous Fast Blue Optical Transients and Type Ibn/Icn SNe from Wolf-Rayet/Black Hole Mergers