One of the largest known stars in the universe is shrinking rapidly, and astronomers don't know why.
Betelgeuse (pronounced almost like "beetle juice") is a red supergiant star 600 light-years away in the constellation Orion. From Earth the star is clearly visible with the naked eye as the reddish dot that marks Orion's left shoulder.
Researchers at the University of California, Berkeley, first measured the star in 1993 with an infrared instrument on top of Southern California's Mount Wilson. They estimated the star to be as big around as Jupiter's orbit around the sun.
But measurements made since then using the same instrument show that Betelgeuse is now only about as wide as the orbit of Venus—a size reduction of about 15 percent in 15 years.
The cause of the star's rapid contraction is a mystery. But the team noted that they had observed an unusual big red spot on the star three years ago.
"Maybe there's some kind of instability going on there," said study team member Charles Townes, a Nobel Prize-winning astronomer at the University of California, Berkeley.
"This red spot may be connected with the fact that [Betelgeuse is] gradually shrinking in size."
Collapse or Bounce Back?
A class of stars known as Mira variables are known to swell and contract by as much as 25 percent every two years—at their lowest points Mira stars can completely disappear from view.
Astronomers know how and why Mira stars pulsate, and they know that the pulses are linked to changes in the stars' brightness.
Betelgeuse is a type of variable star, with slight dips in its brightness every few years. (Find out why Betelgeuse is also called the Valentine's Day star.)
But its pulses are nowhere near as dramatic as those of Mira stars, the UC Berkeley researchers say. And on average the star is no fainter now than it was 15 years ago.
"Something unusual is happening with this star. The question is, What's going to happen next?" Townes said.
Betelgeuse is about 8.5 million years old, and astronomers predict it could explode as a supernova at any time. When it detonates, the blast should be clearly visible from Earth.
(Related: "Supernova 'Shock Breakout' Seen From Red Giant—A First.")
"Is it going to keep on shrinking and maybe collapse, or will it oscillate back and forth?" Townes mused. "We don't know."
Findings presented June 9 at the 214th meeting of the American Astronomical Society in Pasadena, California.
Re:Is Betelgeuse becoming less juicy?
« Reply #1 on: 2009-06-18 12:16:25 »
Okay,
Well, Lucifer reassured me that we don't have to worry about Betelgeuse ending life on earth. Seems that some other credible internet resources agree with him (as usual). I still say its an experiment that hasn't been tried before, but I suppose if it explodes it will be a spectacular show regardless. Certainly many prone to that kind of thinking will place religious significance on it.
Re:Is Betelgeuse becoming less juicy?
« Reply #2 on: 2009-06-23 10:28:57 »
Quote:
Seems that some other credible internet resources agree with him (as usual).
[letheomaniac]Well, at least now I know it wasn't a Great Collapsing Hrung disaster. I am, of course, completely unable to explain what a hrung is, or why it would choose to collapse on Betelgeuse. I'm pretty sure I'm not going to die of shame as a consequence of my ignorance though...
Re:Is Betelgeuse becoming less juicy?
« Reply #3 on: 2009-06-29 16:39:08 »
Well it would be interesting of the super nova coincides with 2012 doomsday rants and WTF is with this section of Google Sky and Microsoft Telescope that has not been up dated in 2 years; ...... I've got my 'tinfoil' hat on and am stock piling dry goods in the shelter .....
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