White dwarf has an atmosphere that is almost completely oxygen
DOI: 10.1063/PT.5.029708
Popular Mechanics : There are only about 32 000 known white dwarf stars, and now one of them has been revealed to be unique among all known stars. Discovered by Kepler de Souza Oliveira of the Federal University of Rio Grande do Sul in Brazil and his colleagues, the star, which they dubbed Dox, has an outer atmosphere that is 99.9% pure oxygen. In comparison, Earth’s atmosphere is only 21% oxygen. Normal white dwarfs have atmospheres made primarily of lighter elements, the remnants of the stars’ original material. The researchers say the dwarf star may have been part of a binary system with a Sun-like star. Dox could have siphoned off material from the neighboring star and then exploded as a supernova, expelling the lightest elements and destroying its partner. The mystery is why only oxygen would have been left behind.
