Posted on Wednesday, 4 March, 2020
An artist's impression of the merging stars. Image Credit: University of Warwick / Mark Garlick
Astronomers have identified a 'bizarre' ultra-massive white dwarf star that may be more than meets the eye.
Known as WDJ0551+4135, this intriguing object, which initially appeared to be a single large white dwarf star, is now thought to be two white dwarfs in the process of merging together.
A white dwarf star is essentially what remains of a main sequence star after it has exhausted all of its hydrogen and gone through its red giant phase (the same thing will also happen to the Sun.)
"(Scientists) have discovered an unusual ultra-massive white dwarf around 150 light years from us with an atmospheric composition never seen before," the University of Warwick press release reads.
The find has been described as "the first time that a merged white dwarf has been identified using its atmospheric composition as a clue."
To identify it, scientists used data from the William Herschel Telescope in Spain and ESA's Gaia telescope to determine that the object had an unusually high level of carbon in its atmosphere.
At twice the average mass of a typical white dwarf star, it was clear something was up about it.
"This star stood out as something we had never seen before," said physicist Mark Hollands from the University of Warwick. "We have a composition that we can't explain through normal stellar evolution, a mass twice the average for a white dwarf, and a kinematic age older than that inferred from cooling."
"We're pretty sure of how one star forms one white dwarf and it shouldn't do this. The only way you can explain it is if it was formed through a merger of two white dwarfs."
Thanks to: https://www.unexplained-mysteries.com