http://www.spacetelescope.org/images/html/heic0918a.htmlhttp://blogs.discovermagazine.com/badastronomy/2009/12/23/vampires-and-thrillseekers-rejuvenate-dead-stars/This image was taken by the Advanced Camera for Surveys on board the Hubble Space Telescope. I had to cut it and compress it drastically to get it to fit on the blog, so you very much want to click on it to embiggen it massively and see it in its fully resolved glory.
The image is of the insanely beautiful globular cluster M30, an ancient city of a few hundred thousand stars located 28,000 light years away in the constellation of Capricornus. The cluster is ancient, about 13 billion years old, making it as old or even older than the Milky Way itself. The core of the cluster is unusually dense as such things go, which is why it was studied. Where better to find vampires and thrillseekers?
Like people, stars are born, age, and die. Stars born with more mass tend to die off more quickly, consuming their fuel at far higher rates than their lower-mass brethren. These stars tend to be blue, so in an old cluster like M30 you’d expect to see no blue stars at all; they should all be long gone. And yet, there are quite a few — astronomers call them blue stragglers. Where did they come from?
more at link