ESO unlocks the Keyhole

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Feb 12, 2009
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The European Southern Observatory just released a whoppingly cool picture:


Whoa. That's the Carina nebulosity region, a vast complex of stars, gas, and dust in the southern skies, one of if not the largest star-forming regions in the galaxy. This shows only a piece of it 144 light years across (if it looks familiar, Hubble took a similar shot in 2007). Click the image to get a bigger version, or, if you have the time and bandwidth that could swallow a pineapple whole, try grabbing this 134 Mb TIFF image. I'm serious, don't click that unless you want a seriously big picture. There's also a video zoom-in on the ESO site.

There's a lot to see here! The bright star at the lower left, grossly overexposed, is Eta Carinae. I've written a few thousand words on that beastie, both here and in my book. And you know what that means: one day it'll blow, and when it does, well, yikes. It's one of the most luminous and massive stars in the galaxy, and there's a small but finite chance that it'll go all gamma-ray burst on us some day. Happily, it's not aimed at us if it does, but even as a plain old supernova it's a terrifying object. It's a binary, and one of the stars must have about 100 times the mass of the Sun, pretty much at the theoretical limit of how massive a star can be without tearing itself apart.

I've written about black holes, galaxies colliding, and even the eventual fate of the Universe. I tell you this to put in perspective that objectively, Eta Car scares the crap out of me.

It can't hurt us, so don't worry about it that way. I just mean that the very fact of its existence fills me with awe and a sort of abject terror. Eta Car is 7500 light years away, but it's so luminous it's visible to the naked eye (at that distance, you'd need a pretty good telescope to spot the Sun at all). And that's when it's just sitting there being all stable and calm. In the 1840s it had an explosive event that blew out twin lobes of matter, each with about the same mass as the Sun. This explosion was just shy of a supernova itself, launching all that gas away from the star at a million miles per hour. So think about a single object that can lob 20 octillion tons of gas at that speed, and tell me the Universe isn't the most awesome thing in the Universe.

Yeah, a keyhole. OK.
Next to Eta Car is the famous Keyhole Nebula, named such because some astronomer thought it looked like a old-fashioned keyhole. I happen to think there are other things it looks like, but I'm too polite to say just what. And don't you go shooting your keyboard off in the comments either. This is a PG blog, OK?

Anyway, the Keyhole is clump of gas and dust being pummeled by the forces of the stars around it, as that whole region is. There are two clusters of stars in the image, too, each with several massive members (though not as hefty as Eta, of course) which blow out huge amounts of material, and also flood the region with high-energy ultraviolet light.

All in all, the Carina nebulosity is a gorgeous complex, but it's one of the most dangerous and inhospitable volumes of space in the galaxy. As much as I dream of wandering the Milky Way via warp drive, there are some places I don't mind viewing from a distance.

Credit: ESO