Tuesday, May 20, 2008

Shiny things.

All the breezy spring days lately have me thinking of warm summer nights out under the stars. So I decided to do another astronomy post. The first half of the Messier list is heavy on clusters, so I thought I'd skim through some more of those. So here are some shiny things you might like to take a look at this summer. Most of them I don't know much about other than their names. This is M-9, which is near the center of the Milky Way.

And this is M-10, and it's very close in the sky to M-12, so if you're looking at one, you can probably find the other easily.

This one is M-11, and is called the wild duck cluster. That's duck, with a D. I repeat, duck with a D. Get your mind out of the gutter.

This is M-12. It used to have a million more stars in it, but it lost them. They claim that the Milky Way stole them with it's gravity, but I'm not sure it didn't just set them down on the seat next to it in the restaurant and then forgot to pick them up when it left.

And this is M-13. In "The Sirens of Titan" Kurt Vonnegut wrote "Every passing hour brings the Solar System forty-three thousand miles closer to Globular Cluster M13 in Hercules -- and still there are some misfits who insist that there is no such thing as progress." -- And once, we sent a message there. It was in 1974 and was called the Arecibo message. It was really was pretty boring as such things go. We sent the numbers 1-10, the atomic numbers of the elements found in living organisms, and the most pitiful looking stick figure of a man you can imagine. And we aimed it at a planet that won't be there when the message arrives. Clearly it was done by committee.

This is M-14. In 1938, a nova appeared in this globular cluster, but nobody noticed it for almost thirty years. Then someone who was studying some old photographic plates from the thirties realized that there was a star in one of the pictures that was new. They think it was five times brighter than anything else in the cluster for a brief while.

and M-15, which I actually know a little about.

In the center M15 there are about 15 very hot stars isolated at the core. Scientists think they are the ‘naked cores' of stars that have been stripped of their outer envelope of gas. This could only have happened if stars were so crowded together in the cluster's core that their gravity pulled material from each other. They call it "stellar cannibalism", which kind of sounds like it's cannibalism done really well. Here's a picture, just so you know what a stellar cannibal looks like.

1 comment:

Tara said...

Well a a stellar cannibal looks very pretty, I think.