Nova T Pyxidis

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From 1890 to 1967, a tiny star in the constellation Pyxis flared up five times -- an average of about once every 20 years. But it hasn't made a peep since. That's led astronomers to suggest that a future outburst could be a doozy -- the star could blast itself to bits as a supernova.

The star is known as Nova T Pyxidis. It's actually a system of two stars. One of them is a white dwarf -- the small, dead core of a star that was once like the Sun. The other is similar to the Sun.

Although the white dwarf is tiny -- only about the size of Earth -- its gravity is extremely strong, so it pulls gas off the surface of its companion. Much of the gas forms a thin, hot disk around the white dwarf, but some of it slams into the surface. When enough gas builds up, it triggers a thermonuclear explosion known as a nova -- and that's what happened in the earlier flareups.

But a study by astronomers at Villanova says the white dwarf didn't get rid of all the extra gas in these blasts -- it's continuing to build up. The star is already near the limit for how massive a white dwarf can be. When enough extra gas piles up, it'll tip the white dwarf over the limit, and the star will incinerate itself as a supernova. For a while, it'll shine as brightly as all the other stars in the galaxy combined.

The Villanova study says that should happen fairly soon -- on the astronomical time scale: sometime in the next 10 million years.

Script by Damond Benningfield, Copyright 2010

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