There are many amazing celestial bodies in outer space that do not fit into our view. But it is unusual to observe how the boldest theories become reality. So it happened to one of the strangest stars, the atmosphere of which is completely represented by oxygen.
At a distance of 1,174 light years from us is the amazing star SDSS J1240 + 6710, which is also called Dox. This is a white dwarf whose mass reaches only 0.56 solar. It is important to understand that white dwarfs are called dead stars, because they arise as a result of the death (evolutionary transition) of the previous star.
Such objects appear compact, less in mass or converge with solar, but 100 times smaller in radius than solar. White dwarfs are also inferior to our star in brightness. The Dox star could become a typical representative of its star class, if not for its amazing atmosphere, which is 99.9% pure oxygen.
Researchers have never seen anything like it, so this white dwarf is considered a real wonder. The fact is that the standard stellar atmosphere is 90% hydrogen, and the remaining 10% is helium with traces of heavier elements.
Stages of the evolution of a star
White dwarfs are the remaining nuclei from the stars, which have thrown the outer layers into outer space, therefore their atmosphere must have the same composition. Typically, carbon and oxygen, as the heaviest elements, are immersed in the dense star center. Helium and hydrogen are light elements, therefore they are retained in the atmospheric layer. Where did the oxygen on the surface come from? It is worth noting that the remaining 0.1% of the atmosphere is represented by neon, magnesium and silicon. Researchers are still unable to accurately answer how such an object was formed, but they believe that a rare and unique process is to blame.
One of the most likely scenarios describes the existence of a binary star system: a red giant and a white dwarf. At a certain period, the giant began to expand, and the dwarf continued to feed on his gas. As a result, the red giant exploded, and Dox lost all hydrogen and helium due to the blast wave, leaving only pure oxygen.
Researchers see for the first time a dead star, whose atmosphere is completely represented by oxygen (if the star has 99.9%, then it is only 21% in the earth's atmosphere). Now it is important to understand whether this is really a unique object in the Universe or a common phenomenon. If the first option, it will be interesting to understand the mysterious process of its formation. If the second option, then due to the weak brightness level of the white dwarfs, we could have missed many similar objects in the reviews.