Eta Carinae is acting up again!

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crazyeddie

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"So the deathwatch continues." Perhaps in our lifetimes? Cool! :cool:

A Rogue Star Going Wild?

"Attention, astronomers! Please keep a close eye on Eta Carinae! It's acting up again."

OK, that's not exactly how Dan Green worded the announcement in IAU Circular 9094 on November 11th, but the gist of his alert was crystal clear. On August 19th Kris Davidson and Andrea Mehner (University of Minnesota), along with John Martin (University of Illinois at Springfield) and others, used the Hubble's Space Telescope Imaging Spectrograph (STIS) to show that one of the most massive and unstable stars known has surged in brightness over the past six months. Now at magnitude 5.1, it's fairly easy picking with the unaided eye for southern-sky observers. And there's every indication that more surprises are in the offing.

......Now there's evidence that X-rays created as outflowing winds from these heavyweight suns crash together have strengthened and gained energy, "a possible indicator that the star is entering a new unstable phase of mass loss," according to Michael Corcoran (USRA).

http://www.skyandtelescope.com/news/75160377.html
 
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Shpaget

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:eek:
Possible hypernova in our lifetime, and I won't see it just because the Earth is in the way :cry:
 
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robnissen

Guest
If that star goes supernova in my lifetime, I will cash in every frequent flier mile I have to immediately get to the Southern Hemisphere to see it.
 
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crazyeddie

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robnissen":2lb1w0oh said:
If that star goes supernova in my lifetime, I will cash in every frequent flier mile I have to immediately get to the Southern Hemisphere to see it.
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Not necessary to go all the way to the Southern Hemisphere.....it's visible from the tropics in the Northern hemisphere. It skims just below the horizon from my latitude 33 degrees north.
 
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Vax

Guest
If someone could please remove last post I made on here this topic.. For some reason it's here and not where I intentionally posted it :lol:

Does anyone know how far away Eta Carinae is?
 
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MeteorWayne

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Yep, a simple 15 second google search gave that:

Eta Carinae (η Carinae or η Car) is a stellar system in the constellation Carina, about 7,500 to 8,000 light-years from the Sun
 
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Vax

Guest
Well pardon my questions..

Is there any other effects to look out for besides a direct hit from an extremely powerful GRB?
 
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crazyeddie

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Vax":1kvq4sfs said:
Well pardon my questions..

Is there any other effects to look out for besides a direct hit from an extremely powerful GRB?
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It was once thought that the solar system would not be affected if Eta Carinae produced a gamma ray burst, because we are no where near what appears to be the star's rotational axis. However, now that there is evidence that this is a binary star, the direction the GRB would take is less certain. Even if we did take a direct hit, it's so far away it probably would not affect us greatly.
 
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Vax

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Well I suppose that would depend on your definition of "greatly". I mean if a GRB hits us any less than 10,000 ly's away it will incinerate us. Or at least kill our earth's microorganisms starting a chain of extinction's.
 
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MeteorWayne

Guest
A GRB at 10,000 light years would most certainly NOT incinerate us.
 
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Vax

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Sorry I said that, but I guess the distance traveled by the "shockwave" would more correspond to the magnitude of the explosion. You can't really say it couldn't happen, granted it doesn't happen that often if at all, i mean at least up until now.
 
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crazyeddie

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Vax":s0ogzgfb said:
Well I suppose that would depend on your definition of "greatly". I mean if a GRB hits us any less than 10,000 ly's away it will incinerate us. Or at least kill our earth's microorganisms starting a chain of extinction's.
Click to expand...

Uh, no. At that distance, it could deplete the ozone layer, but that would be a survivable event. Our atmosphere would protect us from most of the radiation. Some species would be harmed by the resulting high levels of UV light and some might be extinguished, but it would not be the end of life on Earth by any means.
 
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Shpaget

Guest
GRB are usually short events (lasting between fractions of a second to couple of minutes tops), right?
That would mean that half of the planet and ozone layer would be protected by the planet itself, so even in the worst possible scenario some parts of the Earth would be shielded (Southern half of South America, Australia...). Of course the chances are exactly the same that only the Pacific will be facing the radiation, so virtually no land would be affected.
Am I making sense?
 
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R1

Guest
Eta Carniae does not seem too awful close to Earth at 8,000 lyrs. in view of the Milky-Way/Sagittarius merger.

(The Milky Way's galactic center appears as being only 25,000 lyrs (approx.) away :) )
 
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grokme

Guest
That's kind of freaky to think the thing could have gone off 8,000 years ago and we're still waiting for the end result. We've spent the entire time living out our recorded history and build ourselves up into a civilization that could observe this star and begin to understand it, and it could potentially damage us.

The other thing is what if there's a neighbor closer to Eta that supports life and those creatures are looking up wondering when she will blow. I bet their space program is in high gear.
 
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SpaceTas

Guest
The amateur variable stars observers have been keeping a close eye on it for years. AASVSO, Variable Star Section Royal Astronomical Society New Zealand )
Here's a link (it didn't fit in the preview) to the whole light curve:
http://etacar.fcaglp.unlp.edu.ar/plots/historic.jpg

From Observatorio Astronomico de La Plata

Last eruption in 1840 was a big envelope expulsion.


Yes there would be an effect on the ionosphere. The large super-bursts from gamma-ray repeaters do temporarily weaken ionosphere as x and gamma-rays hit. But it recovers with sunshine. Don't know about effects on ozone layer, but it also is continuously created and so would recover.
 
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silylene

Guest
I'd be more worried about Vega . It is slightly variable, currently only 25 LY away, its proper motion is moving closer to us, and its pole points almost right at us (5 degrees off of a direct line of sight). In 200K years, Vega will become the brightest star in the sky. It is fusing very fast on the CNO cycle, and has perhaps only about 300M more years before it goes boom. By the way, Vega is thought to have planets.

(However, don't worry too much, most likely, Vega will have moved way past us by the time it goes boom.)
 
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grokme

Guest
silylene,

Hopefully in 300k years we can find a way to travel near the speed of light and get within the safe range.
 
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silylene

Guest
I edited my post. I think in all likelyhood it will have passed by us before it explodes. Still, Vega is a very interesting star. A Jupiter sized planet is thought to be orbiting it, and it has quite a debris disk around the star, perhaps from a planetary collision..
 
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grokme

Guest
Silylene,

Sorry, trying to wrap my mind around your last post. Are you saying that it will be far enough away in 300,000 years that it wouldn't have an effect on Earth? How fast is it traveling away from us? It's going to have to make about 3k light years in that time, is that correct?
 
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