The following is an excerpt from the March issue of National Geographic Magazine:
Credit: National Geographic
Our star, the sun, will die a quiet death. The sun's of only average mass, starwise, and after burning through the last of its hydrogen fuel in about five billion years, its outer layers will drift away, and the core will eventually compact to become what's known as a white dwarf, an Earth-size ember of the cosmos.
Art by Mark A. Garlick/National Geographic
Superheated gas swirls around our galaxy's central black hole, Sagittarius A*.
For a star ten times as big as the sun, death is far more dramatic. The outer layers are blasted into space in a supernova explosion that, for a couple of weeks, is one of the brightest objects in the universe. The core, meanwhile, is squeezed by gravity into a neutron star, a spinning ball bearing a dozen miles in diameter. A sugar-cube-size fragment of a neutron star would weigh a billion tons on Earth; a neutron star's gravitational pull is so severe that if you were to drop a marshmallow on it, the impact would generate as much energy as an atom bomb.