Posted on 04/09/2007 12:07:48 PM PDT by bedolido
A star that survived a massive explosion – only to be destroyed in a second blast just two years later – has piqued the curiosity of astronomers. Its bizarre death might be due to the production of antimatter in its core towards the end of its life.
The star that exploded appears to have been a massive type called a Wolf-Rayet star, which begin their lives with more than 40 times the mass of the Sun.
It exploded in a galaxy 77 million light years from Earth, with the first blast occurring on 20 October 2004. It was so bright that the amateur astronomer who first noticed it initially mistook it for a supernova – the final blast that ends a star's life.
But the 2004 explosion was not fatal. The star was observed undergoing a second explosion on 11 October 2006. This one was indeed a supernova, and was named SN 2006jc.
This is the first time that astronomers have witnessed a star suffer a pair of explosions, with the second one ending its life.
(Excerpt) Read more at space.newscientist.com ...
Where’s the blasted photo??? :-)
That's why the Pierson's Puppeteers moved their home-world.
ping.
So it wasn’t from a IED?
I understand what they mean, but that line just sounds a little odd.
Actually, I think the first blast occurred 77 million years ago.
hmmmmmm speed of light... I think it does sound off.
(just posted what they had printed)
Can someone help me out here? If the galaxy is 77 million lightyears away, then presumably the light from this took 77 million years to reach earth, and the event actually happened 77 million years ago. What am I missing?
Yes, you are correct.
It only became apparent to earth in 2004.
The cowards!
it’s got to mean when the scientists first saw the explosion. not when it actually happened.
But we couldn’t date it until we saw it. The scientists, if not the writers, know the difference...
That has to be what they mean but the geek who wrote that sentence in a better scientist than a writer.
Interesting...
IIRC, the chemical elements in a star fuse into heavier elements—H into He, He into C via Triple-Alpha (and a little over 7 MeV), C into O, O into Si, and finally Si into Fe.
The iron core is so heavy it cannot fuse anymore, and it grows—once it passes the Chandrasekhar Limit, the core collapses under its own gravity, decomposing into He, subatomic particles, and shockwaves. Shockwaves compress and shoot out, taking the stellar atmosphere with it.
Could be they’re talking about the possible creation of antihelium upon the collapse of the Fe core which then reacts violently with the surrounding matter.
Just FYI, this means that the first explosion happend on the 20th of October, 76997996 BC. Now I guess that I should don my asbestos suit before I say this, but that was somewhere toward the end of the Cretaceous period. Specifically during the Campanian Epoch. This post will pi** off creationists, global warming alarmists and just about anyone else who flaunts science. If you're wondering why I mentioned global warming, well here's a quote from Wikipedia:
The climate was very warm during the Cretaceous; there was no ice at the poles. Sea level was much higher than today, and large areas of the continental crust were covered with shallow seas; sediment cores show that tropical sea surface temperatures may have been 9-12°C warmer than at present, while deep ocean temperatures were as much as 15-20° C higher than today's.
Perhaps the writer is very geocentric.
“It exploded in a galaxy 77 million light years from Earth, with the first blast occurring on 20 October 2004. “
That is, it exploded October 20, 77,000,000 B.C.
LOL!
October 20th, 76,997,996 BC
A long time ago in a galaxy far, far away...
Actually, I think the first blast occurred 77 million years ago."
IIRC, according to relativity theory, if something is 77 million light years away, then "now" here is equivalent to 77 million years ago there. It's called the relativity of simultaneity and it means that the instant that a beam of light leaves somewhere else is simultaneous, for all practical purposes, with the instant that it arrives here. No other definition of simultaneity makes more sense. At least this is what they taught back in the 1970's. I haven't been keeping up.
How can they be sure it was the same star each time?
If the explosion took place 77 million light years away and it occurred in 2004, it will be another 77 million years before we learn about it.
I bet "journalist" exhibits a similar level of scientific knowledge when writing about global warming.
You can’t fuse iron in the core—the iron absorbs the energy This is why the iron core grows until it exceeds the Chandrasekhar limit.
But particles can be created by collision with particles, and IIRC, this is how the heavier elements formed.
I sensed a disturbance in the force.
Why do I get the feeling that the first transmission S.E.T.I. is going to pick up will be....”Say! What does that button d....”
They're only formed in supernovas.
[if I am understanding your use of the word “now.”]
It depends on what the meaning of now is.
Is that what you are trying to say?
Iron is the energy minimum for fusion. Fusing to iron yeilds energy. To form elements heavier than iron requires energy. A lot of energy is consumed and the pressure in the star’s core isn’t high enough. The burst of energy from a supernova is great enough to form elements heavier than iron. It’s analagous to exothermic vs endothermic reactions in physical chemistry. Nuclear fission is essentially releasing a lot of the energy from a supernova that created the fissile material to begin with.
I hope that doesn't mess up your time calculations folks, but it had to be asked.
bump
If we are seeing light from something 77 million light years away we are seeing light that left it's source 77 million years ago. We are then, in effect, seeing what happened 77 million years ago.
77 million light years. Light does not slow down or speed up relative to the speed of it's source.
Of course we humans will wait until the last minute then run for our lives...but then we have no qualms about using hyperspace like the Puppeteers!
Hmmm...I don't remember that one.
Right, the universe is continually expanding, so are the 77 million light years referring to the distance the planet was from Earth when the light was emitted or is it referring to the current distance? If it is the latter, the explosion occurred before October 30, 76999996 B.C (or whatever that date was).
Niether the Earth nor Galaxy UGC 4904 are stationary. If you believe the expanding universe theory(which there is the most supporting evidence for) they are getting farther away from each other each second.
I was just postulating that we can’t be all that certain about when something happened if we haven’t calculated where the 2 points were at the time of the event. Conversely, without knowing precisely when the event happened, you can’t calculate where the 2 points were at the time of the event. A cosmic catch-22.
Remember the nasty stuff takes longer to get here than the light.
I waded through 30 posts, then hit this one. Thanks for the laugh.
President Bush is to blame for this type of travesty. First the economy collapses and now this galaxy.
Now, I like Astronomy as much as the next science geek, but I hope this is just 'journalistic license'.
Yes, antimatter may have cause the explosion. Or collision with a large, dark partner. Or aliens. Or the Empire.
Just griping. Nothing to add. Sorry.
You did not account for leap years.
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