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Supernova remnant expands as we watch!

1 decade 5 years 3 months 3 weeks ago

From Bad Astronomy:

Astronomers using the Chandra X-Ray Observatory have just released an extraordinarily cool animation. Composed of images taken between 2000 and 2007, it shows the supernova remnant Cas A literally expanding as you watch it!

See the little white dot in the center? That used to be a star, a big one. About 330 years ago*, that star blew up in a titanic supernova explosion. Several octillion tons of material screamed outward from the star at a good fraction of the speed of light, leaving behind an ultradense neutron star, the remains of the star’s core. So, that dot in the center? It’s an object a dozen kilometers across that has about the same mass as our entire Sun. It has a density of about 100 million tons per cubic centimeter. That’s roughly the mass of every single car in the United States, crushed into a cube the size of, oh, say, a mini marshmallow.