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Different Explosions

July 19, 2014

Aquila, the eagle, soars across the southern sky on summer nights. It’s in the east as night falls and high in the south after midnight. It’s marked by Altair, one of the brightest stars in the summer sky.

But almost a century ago, Altair was dwarfed by a “new” star that popped into view near by. Known today as V603 Aquilae, it was a nova — the explosion of hot gas on the surface of a white dwarf. It briefly shined as brightly as any star in the night sky.

Over the decades, astronomers have used various techniques to try to measure the power of nova explosions. These observations seemed to show that all novae were basically alike — they exploded and faded from view in the same way.

Recently, though, a team of astronomers used Hubble Space Telescope to get the most accurate distances yet to V603 Aquilae and three other old novae. The distance of a nova reveals its maximum brightness, providing clues about what’s happening in the explosion.

McDonald Observatory astronomer Fritz Benedict, a member of the Hubble team, explains that the observations showed that nova explosions aren’t all alike:

BENEDICT: The big piece of information is that these things are very individualistic. The assumption that the same energetics are always involved is wrong. We thought we knew what was going on, and now we know we don’t know what’s going on. You look for the “Aha!” moment, but you also have an aha moment when you say, “Ha, we were dead nuts wrong about that, we need to do it some other way.”

So there’s a lot more work to be done to explain the explosions of these “new” stars.


Script by Damond Benningfield, Copyright 2014

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