Star seen hurtling through Milky Way at 550,000 MPH after 'thermonuclear ignition'

The rogue white dwarf blasted out of orbit after the star exploded. Researchers confirmed the star is currently travelling through our galaxy.


And the team believes this could be one of many such supernovas currently speeding through our galaxy unbeknown to us.


And the discovery also suggests there may be other types of supernovae in other galaxies as-yet-undiscovered by astronomers.


When the white dwarf was originally spotted, scientists found the star had an odd atmosphere, leading to further research to understand its unknown origin.


University of Warwick astronomers now believes the star was likely once part of a binary star that exploded in a supernova.


This is supposed to blast it and its partner out in different directions through the galaxy.


The star is travelling at 550,000mph (900,000kmh), those who first discovered it have announced.


The speeding star appears to have a surprisingly low mass, leading scientists to speculate there is a high probability it is the consequence of the supernova explosion.


White dwarfs tend to be almost entirely composed of hydrogen or helium.


The interior of a planetary nebula glows in radiant colours J (Image: Getty)


But since researchers spotted the star, dubbed SDSS J1240+6710, they noted it was instead constituted of an unusual combination of oxygen, neon, magnesium and silicon.


And further examination by the NASA/ESA Hubble Space Telescope revealed the white dwarf also included carbon, sodium, and aluminium in its atmosphere.


These elements happen to be created in the early reactions that make up a supernova.


The star also lacks some of the heavier elements that are normally made up from the lighter ones during the key parts of the supernova explosion.


The scientific team think that indicates the star only went through a partial supernova process, with the nuclear reaction ending before it could finish.


Professor Boris Gaensicke from the Department of Physics at the University of Warwick and lead author said: "This star is unique because it has all the key features of a white dwarf but it has this very high velocity and unusual abundances that make no sense when combined with its low mass.


"It has a chemical composition which is the fingerprint of nuclear burning, a low mass and a very high velocity: all of these facts imply that it must have come from some kind of close binary system and it must have undergone thermonuclear ignition.

"It would have been a type of supernova, but of a kind that we haven't seen before."


The supernova did, however, develop enough to disrupt the star's orbit with its partner in the binary system from which it came.


That probably led to a very fast ejection of much of its mass, sending both stars off in different directions, and explaining the star's strange speed.


Professor Gaensicke added: "If it was a tight binary and it underwent thermonuclear ignition, ejecting quite a lot of its mass, you have the conditions to produce a low mass white dwarf and have it fly away with its orbital velocity."

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