Posted on 09/17/2003 7:27:05 AM PDT by bedolido
A giant star has been caught in the act of swallowing three planets, one after the other, with each "meal" accompanied by a massive eruption.
"It has been suggested in the past that stars might engulf planets in this way, but we believe we have actually caught this action for the first time," says Alon Retter of the University of Sydney, Australia.
The star, known as V838 Monocerotis, is about 20,000 light years from Earth. In January 2002, it temporarily became the brightest star in the Milky Way, 600,000 times more luminous than the Sun. At the time, astronomers struggled to explain the spectacular explosion.
Retter and colleague Ariel Marom believe their new analysis of light emissions from the star indicates that it was a red giant that expanded and successively swallowed three relatively massive planets in quick succession. The time between the first and the last engulfment was only about two months.
"In principle, that explanation seems OK," says John Lattanzio, director of the Centre for Stellar and Planetary Astrophysics at Monash University. But he says the star was too hot to have been a red giant. "It was probably one that was on its way there - that could fit the parameters."
Existing models of what will happen when our Sun expands to become a red giant, in about one billion years, suggest that Venus and Mercury will both be engulfed. The likely fate of the Earth is unclear. "Our work suggests that once one planet is engulfed, there is an eruption, and then further expansion - so it might suggest that Earth will indeed be swallowed. But this will need to be checked carefully with the models," Retter says.
Twin peaks
The light analysed from V838 Monocerotis shows that after a short but gradual decline in luminosity following January's outburst, the star suddenly increased in brightness again in early February. The phenomenon was repeated a third time in March.
Retter and Marom found that each of the three maximum peaks in brightness were followed by secondary, weaker peaks. This repeating pattern suggests each event had the same cause, says Retter. The data also reveals the presence of large amounts of lithium and barium, which astronomers had proposed might indicate that a star had swallowed a planet.
Initially it was suggested that the first explosion was some kind of nova outburst, but this was hard to match to the observations. Other researchers suggested that two stars had collided.
"But again, this cannot explain the complicated light curve," Retter says "Our explanation, that the star swallowed three planets, fits all the observational features of the star."
Retter and Marom describe their analysis in a letter accepted by the Monthly Notices of the Royal Astronomical Society.
Emma Young, Sydney
Afrika Bambaataa/Kraftwerk hip-hop/techno bump
... Existing models of what will happen when our Sun expands to become a red giant, in about one billion years, suggest that Venus and Mercury will both be engulfed. The likely fate of the Earth is unclear. "Our work suggests that once one planet is engulfed, there is an eruption, and then further expansion - so it might suggest that Earth will indeed be swallowed. But this will need to be checked carefully with the models," Retter says.
I really doubt the expanding sun swallowing Mercury or Venus will have much of an effect on the total expansion.
The planets that caused the eruptions in V838 Mon were "relatively massive", probably putting them in a range of 10-20 Mj, possibly up to 35 Mj -- almost enough to trigger fusion on their own, and definately enough to emit more radiation then they absorb.
In terms of mass, the sun swallowing both Mercury and Venus would add .0002 percent more mass to the sun. Now, if the sun were to swallow three 10 Mj planets, it would add 3% to the Sun's mass. Quite a difference.
I thought we had 5 billion years before that happened. What happened to our other 4 billion years?
Time to invest in beachfront property on Mars, I guess.
Jeremy Shockey opened his mouth again???
JK. This is cool stuff. To capture it on film is awesome.
Well, the Giants sure "caught their lunch" on Monday night.
and while police had some difficulty handcuffing the stellar body, he reportedly went without struggle.
"We intend to charge him with Fiery and Disorderly, Disturbing the Cosmos, and Unlicensed Planet Annihilation," said Sheriff Fess Green. "While they may be stars, they are not above the law."
An ecological nightmare!! Evolutionary masterpieces----gone forever!!
And remember----it happened on George Bush's watch!
The image of the 'soap-bubble distribution' of galaxies in the universe is truly striking (but not unexpected).
However, I find the "from the inside-looking out" view of our own galaxy (the blue "sash" across the middle that wraps around the edges) to be profound evidence of where we as a planet -- and as beings -- fit into the whole scheme of things.
The full-size (1496K) image of today's photo (which can be reached by visiting today's APOD page and clicking on the reduced-size image shown above) is absolutely mind-blowing! In it, you can see familiar dust-lane features of our Milky Way galaxy -- especially where it "wraps around" the edges of the image. (...looking back toward galactic center...)
If you think about it and visualize how the image was made (from our viewpoint), you can tell that we are out on one edge of a discoidal mass of stars -- and that the image is as if the 'camera' 'panned' around a circle at right angles to the disc of our galaxy.
Notice that the blue band of our galaxy doesn't wrap completely around the edge of the image; (its form is that of a great "S" lying on its side). Just below center in the blue "sash" is the lowest-density point; I interpret that to be the direction of view out through the nearest edge of our galactic disc.
That's quite an exercise in spatial visualization, but the insights to be gained are well worth the effort... Its ramifications for fundamentalist Creationists (who insist that the Earth and Man are the center and raison d'etre of all Creation ) should strain their simplistic, geocentric, homocentric, and egocentric views of the universe...
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(Let's see how long it takes before someone sneeringly mentions "the E-word"...)
Is Oprah off her latest diet?
Mars will go, too. Take a look at Europa, or as it will be known, Waterworld.
(The photo brings to mind that old image of the galaxy with an arrow pointing to a spot 'way out near the edge -- with the caption, "You Are Here!"...
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