White dwarfs can be helium, carbon-oxygen or supermassive oxygen-neon. However, scientists have come to the conclusion about the possibility of the existence of supermassive dwarfs of another type and explained how they are formed.
New type of white dwarfs
Chinese astronomers have discovered a new type of white dwarfs. These small dense objects are the final stage of evolution for 97 percent of the stars in the Galaxy. They are divided into three types: helium, with a mass of up to 0.45 of the mass of the Sun, carbon-oxygen, with a mass of 0.45 to 1.05 of the mass of the Sun, and oxygen-neon, with a mass of more than 1.05 of the mass of our luminary. The last are called supermassive white dwarfs.
In an article published in Monthly Notices of the Royal Astronomical Society, scientists investigated the distribution of supermassive white dwarfs on the Hertzsprung-Russell diagram and concluded that some of these objects have a significant delay in cooling. And it is characteristic of another type of white dwarfs — carbon-oxygen.
In fact, we are talking about the discovery of a new type of stars — supermassive carbon-oxygen white dwarfs. At the same time, the question immediately arises about the mechanism of their formation. After all, they cannot be created the way previously known types do.
How white dwarfs of a new type are formed
Scientists have suggested that a new type of stellar remains may be formed by the fusion of an ordinary carbon-carbon dwarf with helium. They built a model of this process. It turned out that everything can happen very quickly. At the same time, a hot helium corona forms on the surface of the object.
As a result, an R—type star of the Northern Corona is formed — a replaceable yellow giant, the periodicity of which is caused by the burning of the helium shell. If at the same time, as a result of emissions, the mass of the star decreases to 1.2 times the mass of the Sun, then it becomes a new type of white dwarf. Otherwise, a standard supermassive white dwarf consisting of oxygen and neon will be formed.
According to Рhys.org
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