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Green Star – A new type of star that has never been seen before

A white dwarf is not a star similar to other stars with distinct qualities. Stars like sun use to fuse nuclear material in their cores to control their own weight while white dwarf uses the effect of quantum degeneracy to control its weight. Quantum degeneracy simply means that electrons don’t have the same quantum state. And when you try to compress them in the same state it will deploy the degeneracy pressure that prevents the white dwarf from collapsing.
There is restriction to how much of mass a white dwarf can contain. To calculate this limit Subrahmanyan Chandrasekhar in 1930 found that white dwarf has mass of about 1.4 more than the sun’s gravity that will break the star into black hole or a neutron star. Chandrasekhar limit calculation is based on the simple model where the star is not rotating when it is equilibrium. When two white dwarfs get collide it becomes more complex.

Scientists in 2019 discovered a white dwarf that is similar to other white dwarfs but too bright in nature. Scientists have proposed that this bright object is the merger of two white dwarfs. And to capture the image in the new study a team of scientists have used XMM-Newton X-ray telescope to capture the image of bright object that has mass greater than the Chandrasekhar limit. This bright object is surrounded by remains of nebula with high wing speeds and it is mostly seen as neon or green colour. The colour remains consistent when an object has been created by white dwarf merger. It doesn’t allow the object to fall down into neutron star.
In the next 10,000 years this process will create a supernova and the object will get collapsed to become a neutron star and thereby breaking the Chandrasekhar limit for some time.