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Linné on line arrow Physics and the Cosmos arrow Macrocosmos arrow Galaxies arrow Supernova

Supernova

When a heavy star burns all its light elements a nucleus of iron with very high density is formed. Material that falls into this nucleus will not be able to penetrate it and instead it will bounce off. When this happens large amounts of material will be thrown out into space - a supernova explosion takes place. Stars which are not heavy enough will at first form a red giant and then stop glowing. A less spectacular death.


Photo of the supernova SN1987A with rings from the Hubble space telescope.
 
Remnants of a supernova that exploded about 3000 years ago in the small Magellanic cloud.

Today we do not know where the rings in SN1987A come from. Theories suggest that they may have been created by radiation from the supernova remnant. This radiation interacts with the surroundings and thereby emits light.

Supernovas are quite well understood today and we can study the different phases with modern telescopes. Historically things where different. There were not many supernovas that could be seen with the naked eye or with the simple instruments available. Often they were interpreted as signs of a large catastrophe.