Researchers have discovered a huge star in the shape of a snowman with an unprecedented atmospheric composition.
It has a mass greater than our Sun, but only two thirds the diameter of the Earth.
The object is believed to have resulted from the fusion of two white dwarf stars that often explode as powerful supernovae.
According to researcher Mark Hollands of Warwick University, the team’s discovery may help scientists better understand how this process occurs.
“The most exciting thing about this star is that it barely exploded like a supernova. There aren’t that many big white dwarfs,” he said.
“There is still a lot of uncertainty about what types of star systems reach the supernova stage. Oddly enough, measuring the properties of this ‘failed’ supernova is telling us a lot about the ways of thermonuclear annihilation.”
That’s because a white dwarf is what stars like the Sun become at the end of their lives, when they spend all their nuclear fuel.
It is when they lose most of their atmosphere, leaving a very hot core. The heaviest atoms in its atmosphere sink and the lightest atoms remain on the surface. Some white dwarfs have almost pure atmospheres of hydrogen or helium.
But this star, called WDJ0551 + 4135, has an extraordinarily carbon-rich atmosphere.
“The only way to explain this is if it was formed by merging two white dwarfs,” says Hollands.
Source – Globo