Eta Car: tick tock, tick tock

**Marx** · 22nd-June-2007

So when is the supermassive star Eta Carinae going to blow? No one knows. But at 100 - 150 times the Sun’s mass, it doesn’t have much time left. And the presence of lots of nitrogen in the gas surrounding it is a bad sign: that means that the star was making heavy elements in its core, then belching them up into space. By the time a star like Eta Car is making nitrogen, it doesn’t have long left to go. And when it goes, it’ll go.
The image above is from NASA’s Chandra X-ray observatory. The blue part is an optical image from Hubble, and shows the bipolar lobes of gas ejected when Eta Car had a coughing fit back in the 1840s. That’s 20 octillion tons of gas (20,000,000,000,000,000,000,000,000,000) it ejected at about a million miles per hour, in case you’re not getting enough awesome in your diet.
The yellowish ring is gas the star ejected long ago getting slammed by more recently blown out matter. The gas gets heated to a few million degrees by the impact, and gives off X-rays. By examining the energies of the X-rays, astronomers have found the ring is rich in nitrogen, and that’s the bad thing. Stars like the Sun fuse hydrogen into helium in their cores. If the star is really massive, then it can fuse helium into carbon once the hydrogen in the core is used up. Then it can fuse carbon into neon, and up the periodic table until it hits iron. Stars can’t fuse iron in their cores, which takes away the source of support for the zillions of tons of gas in the star. It collapses, and then complicated stuff happens (forgive me, I just wrote a long chapter for my next book about this, and I don’t wanna repeat myself right now… but I wrote a description of how this works on my Bitesize pages), and then the outer part of the star explodes. The inner part collapses down into a neutron star or a black hole.
Usually, a star like Eta Car can go through its hydrogen in a few million years. But each element fuses more quickly than the last, and by the time neon or oxygen is fusing, the star has literally centuries left at most. The presence of nitrogen in the gas means there was time to make that much of it, get it to the surface, expel it, and let it expand for a while.
So Eta Car is ticking bomb. It could go off tonight, or in the year 3000 (did Futurama ever cover this?), but it won’t be much longer than that.
Note that the lobes appear to be tilted away from us by about 40 degrees or so. That’s a good thing. When stars like Eta Carinae explode, they tend to shoot of beams of energy and matter that, at its distance of 7500 light years, could kill every living thing on Earth. But since it’s pointed away from us, all we’ll get is a spectacular light show. If you’re keeping score at home, gamma-ray burst aimed at you = bad, pretty supernova with no accompanying high energy radiation = good.
I just wrote a lot about Eta for my upcoming book, so if you like this kind of stuff you’ll love that chapter. It gave me the creeps, so I’m glad I’m done with it. Now I’m off to write about black holes devouring the Earth…

**chevalier** · 22nd-June-2007

That was a very interesting post. I love stuff like this I'm trying to find a book on String Theory that I might be able to understand. I also enjoy watching shows on black holes ,quantum mechanics,astro physics and futurama bender and zoidberg kill me. Are you writing a book Marx? Or is this an article that you placed here?

**Marx** · 22nd-June-2007

http://www.badastronomy.com/bablog/2...ock-tick-tock/

I nabbed it from the above url

**FFFF** · 22nd-June-2007

We are, of course, doomed.. The cosmic reality of life is that we will either be fried or freeze within the next few billion years..

Mind you, when discussing cosmic matters, time is a strange thing..

**Fruit_Cake** · 22nd-June-2007

my dad taught me the names of most of the stars when i was little, cant remember them now though. beteljuice alpha centaurai

**Marx** · 22nd-June-2007

I rather enjoy the night sky... Patrick Moore is a cool dude, even if he is old.

**FFFF** · 22nd-June-2007

Quote from Fruit_Cake

my dad taught me the names of most of the stars when i was little, cant remember them now though. beteljuice alpha centaurai

Interesting, we have trillions of stars our the local galaxy, called the milky way, and there are many millions of other similar galaxies out there, most of them only recognisable as clusters as they are so far away..

So, No wonder you cant remember the names of most of the stars!

Sirius is my favourite one.. You find that by taking a trip down Orions belt, which is under Betelgeuse on Orions shoulder..

Andromeda is on a collision course with the Milky way, and guess what happens when galaxies collide?

(The answer is very little, because the stars are so vastly spaced apart that the likelyhood of collision is neglegible!)

**Marx** · 22nd-June-2007

Quote from Drex

(The answer is very little, because the stars are so vastly spaced apart that the likelyhood of collision is neglegible!)

As it happens, I was reading up on this only days ago...
Andromeda also collided - in a hit & run style - with another galaxy a few billion years ago, leaving it severely depleted of its resources, and somewhat of a dent in it's formation. Similar is predicted for our Milky Way. Especially as our Galaxy is considerably smaller than Andromeda Galaxy. Another potential scenario that has been put foward is that some of the energies from the 'weaker' galaxy (read: ours) may be shot off, like a sling-shot.
Yeah, it could get ugly. Luckily, this won't be for a few bits of an gazzillion years or so.

**FFFF** · 23rd-June-2007

Most things in space dont involve direct collisions, they tend to be a matter of the approaching high speed objects get stuck into a balancing orbital situation..

The nearest star is 4 light years away, the suns diameter is about 1 light second.. Matter in the universe is pretty thin on the ground even within galaxies!

Comets are one of the most interesting things, lumps of shite from a cloud 1 light year away from the Sun peridically and usually unpredictably dropping out and rushing in to the Sun in a highly eccentric Orbit..

I have lived my life from the age of 6 with the sure and certain knowledge that the sun will fizzle out one day, if we are not blasted before then!

So, our top priority is to ensure that mankind evolves into something that is able to handle that situation, and it looks like in the last 40 years we have been more interested in making sure our society is able to spend its resources pandering to the petty desires of the gender that prefers to spent its resources on fashion and holidays rather than advancing technology to cope with the evolutionary requirements..