Betelgeuse, sharper view

bojan · #1 29-07-2009, 06:11 PM

http://www.eso.org/public/outreach/p.../pr-27-09.html

renormalised (Carl) · #2 29-07-2009, 06:30 PM

Very interesting article. Amazing piccies.

Benno85 (Ben) · #3 29-07-2009, 09:04 PM

Imagine bearing witness to a Betelgeuse supernova...ahhh the mental image that brings...

Robh (Rob) · #4 29-07-2009, 09:22 PM

The resolving power of these VLTs is astounding, 0.037 seconds of arc and better.
Interesting article. Betelgeuse will be even more fascinating to look at in my little scope.

Regards, Rob.

renormalised (Carl) · #5 29-07-2009, 10:25 PM

Quote:

Originally Posted by Benno85

Imagine bearing witness to a Betelgeuse supernova...ahhh the mental image that brings...

How's about Betelgeuse and Eta going off at the same time!!!!

Now that's what I would call fireworks!!!!

Robh (Rob) · #6 29-07-2009, 11:17 PM

Quote:

Originally Posted by renormalised

How's about Betelgeuse and Eta going off at the same time!!!!

Now that's what I would call fireworks!!!!

Kaboom!
I wonder how bright the night sky would be and for how long?

Regards, Rob

renormalised (Carl) · #7 29-07-2009, 11:31 PM

It would be rather bright...let's just say no more faint fuzzies for a few months!!!!.

glenc (Glen) · #8 02-08-2009, 01:23 AM

Some interesting numbers.
1. Astronomers predict that it's doomed to explode as a supernova soon, within 1,000 years or so ... (Conceivably, it's already happened!)
2. Using this setup's resolution of just 0.009 arcsecond ...
3. ... its diameter has shrunk by some 15% since 1993.
http://www.skyandtelescope.com/news/52184407.html

CoombellKid · #9 02-08-2009, 01:46 AM

I knew there was a reason I couldn't sleep, I had to get up and read this
story. And a great read it was.

It's amazing to think it has lost so much mass in such a short time. You
would have to think something was about to happen.

Cheers,CS

seanliddelow (Sean) · #10 02-08-2009, 11:26 AM

Quote:

Originally Posted by renormalised

How's about Betelgeuse and Eta going off at the same time!!!!

Now that's what I would call fireworks!!!!

Wouldnt the combined radiation be enough to cause cancers?

renormalised (Carl) · #11 02-08-2009, 12:46 PM

Quote:

Originally Posted by seanliddelow

Wouldnt the combined radiation be enough to cause cancers?

No, the amount of radiation you would get from both going off at the same time would barely raise it above background levels. You have to remember, one is 640 light years from us and the other is 8000 odd.

Now, if you were within 30-100 of Betelgeuse or 1000 of Eta, that would be a different matter entirely. Eta is a much larger star than Betelgeuse and will subsequently go off with a much larger bang. What's worse, if Eta goes off as a pair-instability hypernova and forms a gamma ray burst, any habitable planets lying within a 10-20 degree offset from it's axis of rotation, anywhere in the galaxy, will get fried by a massive burst of radiation. It'd be like standing in front of the main beam of the LHC when they fire it up!!!. Luckily for us, we're nowhere near the axis of rotation of Eta. However, there is another LBV (Luminous Blue Variable) near the core of the Galaxy, can't remember it's designation offhand, but for that one, we're almost smack bang in it's sights. If it went off in the last 28000 years or so, then we're stuffed, but they don't think it's quite ready yet. By the time it is, we'll be out of the way.

Here's a good article on Eta Carina

seanliddelow (Sean) · #12 02-08-2009, 02:32 PM

Some scientists think that some of the mass extincions were caused by nearby supernova. I guess if we were close to eta or betelguese we would be fried chicken. Is Eta and Betelguese moving further away from us?

renormalised (Carl) · #13 02-08-2009, 02:58 PM

Quote:

Originally Posted by seanliddelow

Some scientists think that some of the mass extincions were caused by nearby supernova. I guess if we were close to eta or betelguese we would be fried chicken. Is Eta and Betelguese moving further away from us?

Yep, fried...and we wouldn't be coming with 11 secret herbs and spices!!!

Eta is moving towards us at 25kms, Betelgeuse is moving away at 21kms. However, at those speeds, neither star will come even close to us. Over the remaining lifetime of those stars, it amounts to a 100 light years or so. Nothing, really.

seanliddelow (Sean) · #14 02-08-2009, 03:19 PM

I hope i see them explode in my lifetime.....it would be awesome to see through my telescope. Im sure trevor (TJD) will agree with me.

renormalised (Carl) · #15 02-08-2009, 03:51 PM

Quote:

Originally Posted by seanliddelow

I hope i see them explode in my lifetime.....it would be awesome to see through my telescope. Im sure trevor (TJD) will agree with me.

They'd actually be too bright to view through a scope. It'd hurt your eyes...as a matter of fact they'd be bright enough to make you squint your eyes if you looked directly at them. They'd be very bright point sources of light, which is harder to look at than something like the Moon, which is an extended source.

sjastro · #16 02-08-2009, 04:02 PM

For your common garden variety type I and most type II supernovae we should be OK if we are beyond 50 light years of the source.

Some type II supernovae will collapse to form a Kerr type (rotating) black hole which is believed to be the progenitor of GRBs.

As Carl states if we are at or near the line of sight of the axis of rotation of the black hole we could could be in the line of fire of extreme high energy gamma radiation. The "safe" distance would be in the magnitude of thousands of light years.

Our demise would be caused by the destruction of the ozone layer.
When ozone absorbs UV radiation, ozone breaks down into oxygen atoms and molecules. Oxygen atoms being chemically reactive can recombine to form ozone so there is no net loss of ozone.

Gamma radiation on the other hand not only breaks down ozone but strips off the electrons which prevents ozone from reforming.

So if we were able to survive the initial blast of the supernova we will probably end up succumbing to solar radiation and/or the extreme climate change that would occur due to a non existent ozone layer.

Steven

seanliddelow (Sean) · #17 02-08-2009, 05:19 PM

Quote:

Originally Posted by renormalised

They'd actually be too bright to view through a scope. It'd hurt your eyes...as a matter of fact they'd be bright enough to make you squint your eyes if you looked directly at them. They'd be very bright point sources of light, which is harder to look at than something like the Moon, which is an extended source.

I would wear glasses to look at them.

renormalised (Carl) · #18 02-08-2009, 05:40 PM

The blast of gamma radiation would be the equivalent of over 1000 Hiroshima sized bombs going off on every square metre of the surface of the planet. Unless you were in a deep underground shelter or behind a substantial amount of lead, you could turn on the "bend over and kiss your backside goodbye" sign for every living thing on the surface of the planet. The planet would effectively be sterilised.

glenc (Glen) · #19 06-08-2009, 12:37 AM

The sharpest image ever of Betelgeuse shows a mammoth star that is slowly evaporating...http://antwrp.gsfc.nasa.gov/apod/ap090805.html

Morepower (Craig) · #20 06-08-2009, 12:32 PM

Have any of you guys gone out and had a look at it lately ? As in the last couple of days ? If so did you think it was alot brighter than it was when it was in the evening sky ? I'm curious to know as I thought it did.