A Journey To Deep Space

A Journey To Deep Space & The Edge of Forever. A new study authored by University of Utah astrophysicist Paolo Gondolo shows that the first stars, born nearly 13 billion years ago, may have been 400 to 200,000 times larger than our sun and heavily influenced by dark matter, an invisible element that scientists say makes up most of the universe. Those "dark stars" were named by Gondolo's colleagues astrophysicist Katherine Freese of the University of Michigan at Ann Arbor, and graduate student Douglas Spolyar of the University of California at Santa Cruz, after the song "Dark Star" by The Grateful Dead. They may still be in existence, though they don't produce light and instead likely emit infrared energy, or heat, which can be picked up only by space-based telescopes. Astrophysicists previously thought dark matter played heavily into the formation of the universe, but never the formation of the earliest stars. Previously, stars were thought to form when hydrogen and helium atoms clumped and swirled together in what's called a proto-stellar cloud. They began to cool and collapse and become denser. That cooling and shrinking continues until the fusion of hydrogen into helium begins, which causes the star to emit light, Gondolo said. The new findings suggest that dark matter interacted and broke down, producing heat instead of light. As a proto-stellar cloud of hydrogen and helium tried to cool and shrink, the dark matter would keep it hot and large, preventing fusion from making the star shine. "A star that . . . is not powered by nuclear fusion is a unique thing," Gondolo said. "It may point to the nature of dark matter." The research has several implications for the study of the creation of the earliest stars, including how black holes may have formed in the relatively short time frame of 10,000 to 100,000 years.

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YouTube | December 4, 2007

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