dipper@utastro.UUCP (Debbie Byrd) (07/10/85)
There are stars in our galaxy made of atoms crushed to an extreme density. More on neutron stars -- after this. July 10 Neutron Stars All ordinary matter is made of atoms. But atoms themselves are mostly emptiness. In the depths of space there are some stars NOT made of ordinary atoms -- not mostly emptiness. They're called neutron stars. An atom of ordinary matter has a small ultra-dense core called a nucleus -- surrounded by a cloud of electrons, spaced very far away from the nucleus. If the central nucleus were the size of a golf ball, then the surrounding electrons would be several miles away. In other words, the densest matter on Earth is really practically a vacuum-- since atoms themselves are airy, mostly-empty structures. But neutron stars AREN'T mostly emptiness. Many form as a result of gigantic stellar explosions called supernovae -- when a massive star's outer layers blow off, and its inner core collapses. The atoms in the core are crushed into what are called neutrons -- massive particles with no electric charge. The spaces between the nuclei and their surrounding electrons disappear -- and the density of the star becomes almost inconceivably great. If our sun became a neutron star, its former diameter of more than 800 thousand miles would be squashed down to only 10 miles. One little chunk of the neutron star, as tiny as a sugar cube, would weigh 100 million tons! By the early 1930s astrophysicists already had realized the probable existance of neutron stars. But they were actually discovered in the galaxy only beginning in 1968. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin