Word: dwarf
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...collapse stops after several intermediate steps when the stellar material is compressed so much that its atoms virtually touch, forming what physicists call degenerate matter; what prevents further collapse is the tendency of the atoms' negatively charged electrons to repel one another. The star has become a white dwarf. Says David Branch, an astrophysicist at the University of Oklahoma: "It's the size of the earth but has the mass...
Degenerate matter is so resistant to further compression that nothing much can happen to a white dwarf unless, as is common in the Milky Way, it is part of a binary star system. If it is, the white dwarf's powerful gravity can draw gaseous matter away from its companion. In some cases, as the dwarf becomes bloated with its companion's substance, gravitational pressure triggers a fusion reaction in the captured gases, which are blown off in the explosion, resulting in a garden-variety (nonsuper) nova. According to Astrophysicist Branch, about 50 novas are observed flaring up each year...
...just the atoms that are touching, as in a white dwarf, but their nuclei. Under the immense pressure, the electrons, no longer able to repel one another, are squeezed into the nuclei, which ordinarily contain just protons and neutrons. In about a thousandth of a second, the negatively charged electrons combine with positively charged protons to form additional neutrons; the process also produces the ethereal neutrinos, which effortlessly zip through the star's outer layers and into space. Under these circumstances, there is a limit to how much the neutrons can be compressed. As gravity tightens its grip further...
...earth, but with 60% of the sun's original mass, glowing blue-hot at perhaps 120,000 degrees C. That stage will mark the end of the sun's active life; its nuclear fires will never again turn on. Slowly it will cool until it is first a white dwarf, still glowing, then a cold black dwarf, a cinder. In the blackness of space, as in Fire and Ice, the lifeless earth will pass into an eternal deep freeze...
...nuclear fuel and collapses under its own weight. When its matter, falling in from all directions, meets at its center, a shock wave bounces back out in a tremendous explosion that blows apart the star's outermost layers. A Type I explosion occurs when a gravitationally powerful white dwarf star that is part of a binary star system draws gas from its nearby companion. When it accumulates too much, reaching a critical mass about 1.4 times as great as our sun's, it blows...