Astronomers observed, for the first time, signs of double detonation of a star Not final gives life.
An international team of astronomers obtained, for the first time, visual evidence of a star that ended his life with two successive explosions. A discovery that sheds a new light on the role of the supernovae in the evolution of the universe.
The discovery was made to study the remains – with hundreds of years of age – from supernova SNR 0509-67.5, located in the large cloud of Magalhães, with the help of Very Large Telescope (VLT) of And today published in the magazine
Astronomers found standards that confirm that the star that gave rise to him – a white dwarf – suffered a double detonation.
What is a supernova of type
“Most of the supernovae originates in the explosive death of massive starshowever, there is a type that supernova that originates from more modest stars: thes white dwarfssmall inactive nuclei that remain after stars like our sun burn their nuclear fuel can give rise to what astronomers call a Supernova of type Ia “, .
“The explosions of white dwarfs play a crucial role in astronomy“Says Priyam das, a doctoral student at the University of New South Wales Canberra, Australia, who led the study.
Much of our knowledge about the way the universe expands based on AI -type supernovae, which are also the main iron source of our planetincluding the iron we have in the blood.
“However, and despite its importance, the longtime mystery of the exact mechanism that triggers its explosion continues to resolve“adds Priyam das.
More acceptable theory about the origin of the type supernovae
If a white dwarf is part of a binary system, at one point it begins to attract the mate star. When it reaches a particular critical mass – known as ChandraSekhar’s limit – he explodes.
This is the most accepted scenario. However, scientists have been suspected of an alternative for several years.
The theory of double detonation
Recent studies suggest that at least Some type supernovae were better explained by a double explosion triggered before the star reaches this critical mass.
According to this hypothesis, The white dwarf accumulates around it a robber stolen helium cloak, which can become unstable and set on fire.
The first explosion triggers a shock wave that causes a second explosion, this time in the star’s core, and that ends up for giving rise to Supernova.
So far, this theory had never been confirmed with visual evidence. But astronomers already predicted that if it was true, The remains of the explosion would display a peculiar structure, such as a kind of fingerprint: two separate calcium shells.
The distribution of calcium in the remains of Supernova SNR 0509-67.5, in shell form.
That/p. Das et al.
It was precisely this pattern that the team now identified in Supernova SNR 0509-67.5, with the help of the Muse instrument, coupled to ESO VLT. The calcium layers (visible to blue in the ESO image) They confirm the occurrence of a double detonation, even before the white dwarf reaches the critical mass.
“This is a clear indication that white dwarfs can explode before reaching ChandraSekhar’s famous mass limit and that the ‘double detonation’ mechanism actually occurs in nature”Says Ivo Seitenzaahl, who led the observations and worked at the Heidelberg Institute of Theoretical Studies at the time of the study.
The importance of this discovery
Type Supernovas are fundamental to understand the universehe explains The statement of ESO. Its shine helps astronomers measure distances in space, as a “cosmic ruler”.
It was thanks to this method that it was discovered in 1998, The accelerated expansion of the universe – a discovery that earned the Nobel Prize in Physics in 2011.
For Priyam there is also another reason to study these explosions. “This tangible proof of a double detonation not only contributes to the resolution of a longtime mystery, but also offers us a magnificent visual show”He says describing the“Beautiful structure in layers“That a supernova creates. For the astronomer,”reveal the internal functioning of such a spectacular cosmic explosion is very rewarding”.
