First image of the remains of a dead star in a double explosion

The traces of a double explosion which led to the destruction of a star were observed by European astrophysicists who bring by the very fact a first visual proof of this previously theoretical scenario.

The vast majority of supernovas are born following explosions of massive stars, but a number of them comes from a more discreet source: the white dwarfs.

D’octile to supernova

From a mass similar to that of the sun, the white dwarfs concentrate their material in a much smaller volume. They are deemed to end their existence by turning slowly, to become black dwarfs – theorized without ever having been observed – or by exploding in supernova.

The explosions of white dwarfs play a critical role in astronomynoticed in a press release from the European Austral Observatory (ESO) the doctoral student Priyam Das, the first author of the study published in Nature (new window) (in English).

Especially because these events produce a number of elements, including iron, which will serve as a raw material to form new stars. Despite this, The long -standing puzzle of the exact mechanism triggering the explosion remains unresolvedaccording to Mr. Das.

All the models agree on a scenario where the white dwarf accumulates matter by stealing it from a twin star, until imploding under its own mass.

The flight hypothesis

However, recent studies have pointed out towards a second possibility, in which the white dwarf is dragging itself in a stolen helium blanket with its partner, and which can become unstable and detonatesaccording to the press release. The shock wave of this blast would then compress the white dwarf, which would in turn explode in supernova.

Thanks to the Muse instrument installed on the very large telescope of the European Austral Observatory (ESO) in Chile, the team of astronomers captured a photographic instantaneous Remains of the event, called SNR 0509, and occurring around 300 to 330 years ago in the Magellan cloud, close to the Milky Way.

In accordance with theory, these images show two distinct rings of calcium, colored in blue in the images of Muse, each corresponding to an explosion.

It is a indication claire what the double detonation mechanism takes place in natureaccording to astronomer Ivo Seitenzahl, of the German Institute of Heidelberg for theoretical studies, which led observations.