On April 5, 2016 (February 28, 2016 in the lunar calendar), scientists discovered a rare white dwarf star filled with pure oxygen atmosphere. The white dwarf discovered this time is different. There is no mixture of light matter on its surface, except for pure oxygen. On April 5, 2016, according to foreign media reports, two researchers from Rio Grande do Sul Federal University and a researcher from the University of Kiel made a unique discovery. They discovered a white dwarf whose atmosphere is almost full of oxygen. The three researchers, Keplerde Souza Oliveira, DetlevKoester and Gustavo Ourique, co-signed a paper published in the journal Science, in which they explained the process of discovering the white dwarf star and their thoughts on the existence of the white dwarf star. Scientists believe that white dwarfs are formed when a relatively small star loses energy, shrinks by gravity and loses outer material. Strong gravity usually causes the heaviest elements in a star to sink to its core, pushing lighter substances such as helium and hydrogen up to the star's surface. But according to scientists, the white dwarf discovered this time is different. There is no mixture of light matter on its surface, except pure oxygen. The white dwarf star, nicknamed Dox, is the first star to have an atmosphere almost entirely of oxygen. Although scientists have predicted the existence of such phenomena, few in the scientific community believe them, so the discovery is a surprise for research team member Gustavo Ourique. After further testing, it was finally confirmed that what he discovered in thousands of images taken by the New Mexico Observatory was a unique object, and the image data source was this white dwarf star. Although it is impossible to explain how this particular white dwarf star formed, scientists believe Dox may have been a group of stars that formed binary stars in the past, one of which lost energy and became a red giant. Researchers believe a subsequent explosion caused Dox to lose its lighter substance, leaving pure oxygen on its surface.