2009/11/05 by Ruediger Pakmor, Rüdiger Pakmor, M. Kromer +8 · 5 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Common envelope #Gamma-ray bursts and supernovae #Light curve #Nuclear physics #Physics #Plasma #Stars #Stellar, planetary, and galactic studies #Supernova #Thermonuclear fusion #White dwarf #astro-ph.HE
paper · pdf · doi:10.1038/nature08642
Accepted to Nature
arxiv created 2009/11/05 · openalex publication_date 2010/01/01 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Type Ia supernovae (SNe Ia) are thought to result from thermonuclear explosions of carbon-oxygen white dwarf stars. Existing models generally explain the observed properties, with the exception of the sub-luminous 1991-bg-like supernovae. It has long been suspected that the merger of two white dwarfs could give rise to a type Ia event, but hitherto simulations have failed to produce an explosion. Here we report a simulation of the merger of two equal-mass white dwarfs that leads to an underluminous explosion, though at the expense of requiring a single common-envelope phase, and component masses of ~0.9 Msun. The light curve is too broad, but the synthesized spectra, red colour and low expansion velocities are all close to what is observed for sub-luminous 1991bg-like events. While mass ratios can be slightly less than one and still produce an underluminous event, the masses have to be in the range 0.83-0.9 Msun.