Two Dying Red Supergiant Stars Produced Supernovae

The Crab nebula is the result of a type II supernova explosion observed by Chinese astronomers in 1054. The nebula consists of the outer parts of a red supergiant that exploded after having burned all its fuel. The nebula is still expanding into the surrounding interstellar medium with velocities of several thousand kilometers per second. In the middle of the nebula there is a neutron star, which is the collapsed central, dead core of the exploded star. (Credit: Hubble Space Telescope)

From Science Daily:

ScienceDaily (Mar. 20, 2009) — Where do supernovae come from? Astronomers have long believed they were exploding stars, but by analysing a series of images, researchers from the Dark Cosmology Centre at the Niels Bohr Institute, University of Copenhagen and from Queens University, Belfast have proven that two dying red supergiant stars produced supernovae. The results are published in the journal Science.

A star is a large ball of hot gas and in its incredibly hot interior hydrogen atoms combine to form helium, which subsequently forms carbon, other heavier elements and finally iron. When all the atoms in the centre have turned to iron the fuel is depleted and the star dies. When very large and massive stars, that are at least about eight times as massive as our sun, die, they explode as supernovae.

Read more ....