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fossil fish

White Dwarf Stars and the Age of the Galaxy is designed to facilitate collaborative research on white dwarfs, and to offer curriculum and training opportunities to teachers of students grades 9-12.

The work is a collaboration of researchers from The University of Texas at Austin, The University of Arizona, The University of Delaware, Florida Institute of Technology, and US Naval Observatory, Flagstaff.

White Dwarf Stars

Like living things, stars are born, live long lives, then die. On earth, we find the remains of life forms that lived millions of years ago. Replacing once living tissue, minerals and crystals preserve characteristics of former life forms as fossils. After most stars complete their lives, shining with the energy released from nuclear fusion, they condense and settle into hot, superdense spheres approximately the size of Earth - a white dwarf. Since the number of "fossilized stars" is almost as great as the number of living stars, white dwarfs are abundant in our Galaxy.

Although they are abundant, as they cool, white dwarfs fade and become difficult to detect with telescopes. But they cool on a schedule dictated by their mass, much like a hot iron cools.

Slowing the cooling, white dwarfs have thin, insulating blankets on their surfaces - their atmospheres. Still, the cooler the white dwarf, the older it is. By calculating the temperatures of many white dwarfs, astronomers can date our galaxy, the Milky Way, to constrain theoretical models of stellar evolution and galactic evolution.

planetary nebulae

This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. NAG5-13070 issued through the Office of Space Science and by the National Science Foundation through Grant AST-0307315.

12 January 2006
Astronomy Program · The University of Texas at Austin · Austin, Texas 78712
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