Which star is the largest?

VY Canis Majoris measures 2,600 times larger than the Sun. Image: NASA

The red hypergiant VY Canis Majoris holds the current distinction for being the largest star ever observed, in terms of volume, measuring 2,600 times larger than the Sun.This giant shines much more brightly than the Sun–up to a half-million times as luminous. It can be found in the constellation Canis Major, but in spite of its size and brilliance it cannot be seen with the naked eye because it is 4,900 light-years away. Stars that size live hard and die young. After only a few million years–a short time for a star–there was little hydrogen left to fuel VY Canis Majori’s core. Once the hydrogen was depleted, the star’s core collapsed and got hotter while its outer layers swelled and its surface cooled, transforming it into the red hypergiant we see today.

Due to its size, VY Canis Mayoris is very unstable, and over the past thousand years it has ejected large masses of matter. Sometime in the next 100,000 years, VC Canis Majoris will explode as a supernova–leaving just a neutron star or a black hole behind.

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