Unusual type Ia supernova reported in Nature this week

IFA's Max Strizinger is coauthor of a paper titeled "A hybrid type Ia supernova with an early flash triggered by helium-shell detonation", published in Nature 5 October 2017

2017.10.08 | Ole J. Knudsen

[Translate to English:] Supernova SN 2016jhr blusser kraftigt op fra 4. til 5. april 2016

The large japanese Subaru telescope in Hawaii is equipped with a superfast supernova hunting instrument; MUSSES - MUlti-band Subaru Survey for Early-phase SNe Ia”. In this new Nature-paper the main author Ji-an Jiang of University of Tokyo with a long list of international cooperators describe the discovery of an unususal variety of the elsewise rather ususal supernova type Ia.

 

It is known that a type Ia supernova explosion occurs in a binary star system, but the excact process has been debated for years. The two main theories concern either a merger of two white dwarves late in their life or the influx of stellar gases from a larger companion star to a close white dwarf until it reaches the critical chandrasekar limit, causing it to become unstable and explode. Possibly both types of explosions are possible. The discovery with MUSSES of a type Ia supernova only one day after it occurred has shed new light on the controversy. Because of the very early discovery of the explosion, it has been possible to follow the development of the process in fine details, and it seems that a third explanation may be possible.

The energy output from the supernova shows an unexpected sudden high rise a few days after the explosion. In the paper the authors suggest that this can be caused by a sudden influx of helium onto the surface of a white dwarf, causing a detonation on the surface. The pressure waves from this nuclear explosion then propagates to the carbon in the core of the star, causing it to detonate as a supernova.

The Nature paper is here:  "A hybrid type Ia supernova with an early flash triggered by helium-shell detonation".

A press release from the University of Tokyo gives further background.

Department of Physics, Public / media, Staff, Students