Supernova around the corner: A star system on an inevitable collision course
Just 150 light years away from us, two white dwarf stars are hurtling towards a gigantic explosion. It is inevitable, but also far in the future.
Artistic representation of the two dwarf stars
(Image: University of Warwick)
A research group from the UK has discovered an extremely rare star system in our cosmic neighborhood consisting of two white dwarfs that are irrevocably heading for a collision and a gigantic explosion. If they extinguish each other in a type Ia thermonuclear supernova, the entire system will be destroyed, the team writes. But because this will only happen 150 light years away from us, the explosion would be ten times brighter in our sky than the moon. But because it will still take 23 billion years until then, we won't get to see it.
No danger for the Earth
Type Ia supernovae are of particular importance for astronomy because they can be used as standard candles for determining distances at intergalactic distances. They are formed when a white dwarf star becomes too massive and explodes, explains the University of Warwick. The research has now been led there. It had already been predicted that most supernovae of this type are the result of two colliding white dwarfs orbiting each other. They had been looking for particularly massive representatives for a long time and have now found what they were looking for. The two stars therefore have a combined mass of 1.56 solar masses, making a final explosion inevitable.
Videos by heise
The two white dwarf stars orbit each other in extremely close orbits, the distance is one sixtieth of the distance between the Earth and the Sun. They would still orbit each other at a leisurely pace, with one orbit taking 14 hours. Over the course of billions of years, they will come closer together and eventually race around each other so that one orbit takes just 30 to 40 seconds. In the end, they would annihilate each other in a quadruple explosion, but this would not be dangerous for the Earth despite the short distance. However, they will not be around for a long time anyway, because the sun will devour them first. The celestial spectacle will therefore have to do without an audience.
"This is an important discovery," explains Ingrid Pelisoli, one of the researchers involved. The fact that such a star system has been discovered in such close proximity is an indication that they are comparatively widespread. The discovery of the system with the designation WDJ181058.67+311940.94 is not the end of the research; the search is now on for further precursors of a type Ia supernovae. This could also bring us ever closer to the actual goal of solving the puzzle of their formation. The discovery is presented in the scientific journal Nature Astronomy.
(mho)
