The Colling White Dwarfs create the quirky slum-green zombie star

A white dwarf is not your specific type of star.

While the main sequence stars such as our Sun fuse atomic material in their cores to prevent themselves from collapsing under their own weight, white dwarfs use an effect known as quantum degeneration. The quantum nature of electrons means that no two electrons can have the same quantum state.

When you try to squeeze electrons in the same state, they exert a degenerate pressure that prevents the white dwarf from collapsing.

But there is a limit to how mass a white dwarf can be.

Subrahmanyan Chandrasekhar made a detailed calculation of this limit in 1930 and found that if a white dwarf has a mass greater than about 1.4 suns, gravity would crush the star into a neutron star or black hole.

But Chandrasekhar’s range is like a simple model. One where the star is in equilibrium and it is not rotating. Real white dwarfs are more complex, especially when they undergo collisions.

Binary white dwarfs are quite common in the universe. Many sun-like stars and red dwarfs are part of a binary system.

Tara J005311 477 shines in X-ray.(ESA / XMM-Newton, L. Oskinova / Univ. Potsdam, Germany)

When these stars reach the end of their main-sequence life, they become a binary system of white dwarfs.

Their orbits may decay over time, eventually causing the two white dwarfs to collide. What happens next depends on the situation.

Often they can explode as a nova or supernova, forming a remnant neutron star, but sometimes they can form something more unusual, most recently in paper form Astronomy and Astrophysics Shows.

In 2019, an X-ray source was discovered that looked similar to a white dwarf but was too bright to be a white dwarf. It was suggested that the object may be an unstable merger of two white dwarfs. In this new study, a team used the XMM – Newton X-ray telescope to capture the image of the object shown above.

He confirmed that the object has mass greater than Chandrasekhar’s range. The super-Chandrasekara object is surrounded by a relic nebula with high wind speed.

The nebula is mostly made of neon, seen as green in the image above. This corresponds to the object created by the white dwarf merger. Its probability is a high rotation, which prevents the object from collapsing into a neutron star.

Eventually, the object would collapse to become a neutron star within the next 10,000 years. This will likely create a supernova in the process. It seems that a white dwarf may break Chandrasekhar’s limits, but only for some time.

This article was originally published by Universe Today. Read the original article.


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