PHOTOS: Hubble's Hottest Science Finds

PHOTOS: Hubble's Hottest Science Finds
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Guessing the Age of the Universe

Resembling a firefly festival, this 2002 Hubble picture of old white dwarf stars helped astronomers pinpoint the age of the universe with unprecedented accuracy.

White dwarfs are the dense cores left behind when sunlike stars die. Measuring the light from some of the oldest known white dwarfs revealed that the burned-out stars are 12 to 13 billion years old.

Since then, astronomers have combined these data with age estimates from a theoretical model of the expansion of the universe, as well as more recent measurements of the diffuse radiation released just after the big bang.

Scientists now say with confidence that the universe is 13.7 billion years old, plus or minus a few hundred thousand years.
—Image courtesy NASA and H. Richer (University of British Columbia)
 
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