Unexplained Shocks Around a White Dwarf Star
How is RXJ0528+2838 creating such shock waves? A recently discovered white dwarf star, the farther left of the two largest white spots, RXJ0528+2838, was found 730 light-years away from Earth. Most stars, when done fusing nuclei in their cores for energy, become red giant stars, the cores of which live on as faint dense white dwarfs that slowly cool down for the rest of time.
Definitely.
It is something that I wouldn't want to be within 30 parsecs of, let alone be viewing with the naked eye. (-:
The paper notes that it isn't certain that this is what happened, since it's looking at the remnants a couple of hundred years after the explosion. But the observations are consistent with what heretofore have been mainly computer modelling. There are discrepancies, but they can be explained by no-one having run the computer models forwards for 2 centuries.
A referenced paper from 2019, discussing said computer modelling, states that the entire double explosion sequence occurs in about 3s in the model.
It has been proposed that Type Ia supernovae (SNe Ia) that are normal in their spectra and brightness can be explained by a double detonation that ignites first in a helium shell on the surface of the white dwarf (WD). This proposition is supported by the satisfactory match between simulated explosions of sub-Chandrasekhar-mass WDs with no surface He layer and observations of normal SNe Ia. However, previous calculations of He-ignited double detonations have required either artificial removal of the He shell ashes or extreme enrichment of the surface He layer in order to obtain normal SNe Ia. Here we demonstrate, for the first time in multi-dimensional full-star simulations, that a thin, modestly enriched He layer will lead to a SN Ia that is normal in its brightness and spectra. This strengthens the case for double detonations as a major contributing channel to the population of normal SNe Ia.
earthling
JdeBP