Astronomers have discovered a star that has an atmosphere made up of 99.9 percent oxygen.
The O²-rich atmosphere was found on a white dwarf 1,200 light years from Earth, in a constellation called Draco it’s believed to be the first time the type of star has been discovered.
The discovery of the star, named SDSSJ124043.01+671034.68 and nicknamed ‘Dox’, was detailed in a research paper published in Science. In the paper the team behind the findings wrote that it was “surprising” to find no hydrogen or helium the atmosphere. To put the O² level into context, Earth’s atmosphere is composed of around 21 percent oxygen.
“After oxygen, the next most abundant elements in its atmosphere are neon and magnesium, but these are lower by a factor of ≥25 by number,” the researchers wrote. Of the known 32,000 white dwarf stars that are known this is the only one that has been found with the composition.
The researchers explained that finding the star confirms a long-held theory and could provide clues to how stars evolve. The team behind the work were surprised by the discovery as it does not fit current theoretic models of what happens to stars when they die.
By looking at the spectral lines — light emitted from objects in the universe the researchers were able to identify the elements that made up the unique star.
Most stars are thought to evolve into white dwarfs, like Dox, these are dense remains of a star that has collapsed on itself. Current theories about stellar evolution state that white dwarfs should be made of helium, carbon or oxygen, with even minuscule amounts of hydrogen and helium floating to the surface, obscuring the star’s composition.
Kepler de Souza Oliveira, from the Federal University of Rio Grande do Sul in Brazil, who led the research, said that the findings were “incredibly unexpected”. He told Popular Mechanics: “We had no idea anything like it could even exist, that made it all the more difficult to find.”
Dox was found by the researchers after they sifted through data captured from the Sloan Digital Sky Survey. The survey has the ambitious aim of mapping the entire universe with the help of a 2.5m wide-angle optical telescope.