Posted on 12/02/2003 6:35:50 PM PST by NormsRevenge
A new close-up view of the violent surroundings of the brightest known star in the Milky Way Galaxy confirms the unstable beast's years are numbered. The study also yields new insight into the huge, eruptive star.
Eta Carinae is 100 times more massive than the Sun and 5 million times as luminous.
The monster, as astronomers have described it, had a dramatic outburst in 1841, shining for a time as the second brightest star in Earth's night sky despite being about 7,500 light-years away, or roughly 1,000 times farther away than Sirius, the brightest star in the sky.
Eta Car, as astronomers call it, could erupt again at any time and will eventually explode in a life-ending supernova event that might be visible during the day from Earth, if anyone is still around to watch.
The 1841 eruption created two massive, mushroom-shaped lobes of material that astronomers now study with high-powered telescopes. Thing is, the stuff in the lobes, along with a constant stream of charged particles still emanating from the scene, obscure the star itself.
The new observations got closer than ever.
Astronomers have still not seen the star, but they used the Very Large Telescope at the European Southern Observatory (ESO) in Chile to examine its immediate surroundings. A study of the data, announced last week, shows Eta Carinae is on the verge of instability, rotating at about 90 percent of the maximum speed possible prior to a theoretical breakup.
The observations, in infrared light, detail a "wind" of charged particles plowing out from the star. Our own Sun produces a constant high-speed outflow known as the solar wind. But it is a mild breeze compared to the stellar wind of Eta Car, which blows off the equivalent of 500 Earth masses every year, said study leader Roy van Boekel of the ESO and the University of Amsterdam.
"If Eta Car goes on like this, all of its estimated 100 solar masses would be blown away in about 60,000 years," van Boekel told SPACE.com. The star's life will be shorter if there are more large outbursts like the one in 1841, when perhaps 10 solar masses were ejected, he said.
It is more likely, however, that Eta Carinae will go supernova long before it simply withers away. That dramatic event could occur within 10,000 or perhaps 20,000 years.
Meanwhile, Eta Carinae shrouds itself in mystery.
"The stellar wind that surrounds it is so dense that basically all photons leaving from the star are absorbed in the wind," van Boekel said. The new observations allowed van Boekel and his colleagues to map the shape of the constant outflows, which in turn provided clues to the orientation and dynamics of the unseen star.
They found that Eta Carinae's stellar wind is elongated in the polar direction. Here's why:
"The stellar wind occurs because atoms at the surface of the star are bombarded with so many photons, that they can be blown away," he said. "The star itself is flattened by the centrifugal force arising from its rotation."
Its diameter at the equator is larger than when measured pole-to-pole.
"This causes the temperature of the star to be higher at the poles, and therefore every square foot of stellar surface at the poles emits more photons than the same area at the equator," van Boekel continued. "As more photons can blow away more atoms, the stellar wind is stronger in the polar direction."
The fresh examination fits neatly with previous examinations of the mushroom shaped lobes, which astronomers call the Homunculus Nebula. The current polar outflows appear to be lined up with the much larger homunculus.
"The assumption is that the major axis of the homunculus coincides with the rotation axis of the star," van Boekel said.
Eta Carinae's nebula is visible from the Southern Hemisphere.
Yup!
Could also mean in ten minutes YOU could look outside and see everything much brighter then normal...
We do have to plan for the future. When I wake up from my deep sleep, I best not have a gut, still have my hair, and one of these stars better blow up.
I thought light speed was was the fastest speed possible...?
Yeah, but the the speed of light is six hundred sixty nine million, six hundred thousand miles per hour.
I expect to see this story on Northeast Intelligence Network tomorrow:
02 December 2003; 0800EST -- UPGRADED TO EXTREME WARNING STATUS: Analysts at Northeast Intelligence Network have tied together several fragmentary Al Qaeda bulletin board messages. Our analysts are continuing their work but have determined the following: Al Qaeda astronomers have closely studied the events on Eta Carinae and determined that the star went hypernova 7500 years ago. The "blast" from this explosion will impact the Earth shortly between the end of Ramadan and Christmas and result in the loss of satellite communications. This is what previous cryptic Al Qaeda messages were referring to when they claimed that Al Qaeda's next strike would "cut America off from communication with its armies in Muslim countries". In the resulting chaos, Al Qaeda terrorists will unleash multiple terrorist attacks worldwide with a possible focus on large cities, small cities, towns, and villages.
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Since the star is 7,500 light years away maybe it already has.
LOL, no fair, you did the Math. And I bet you used a calculator, too.
See if you can come up with the answer Forrest Gump figured on the following question:
"How many seconds are there in a year?"
Actually, there is an easy way to figure this out using your fingers on just one hand.
I'll reveal this method at another time.
More accurately, it began brightening some 7505 years ago and may have already gone supernova but we are just learning about it now.
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