Skip to comments.Astronomy Picture of the Day -- Millions of Stars in Omega Centauri
Posted on 06/15/2011 3:20:01 AM PDT by SunkenCiv
Explanation: Featured in this sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away. Some 150 light-years in diameter, the cluster is packed with about 10 million stars much older than the Sun. Omega Cen is the largest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way.
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[Credit & Copyright: ] Gordon Mandell
Whoever would sleep near such a thing, probably needs sleeping pills.
Lovely! Thanks, Civ!
Fun to look at from a distance, but probably not very healthy close up. With an average distance of about .83 ly between stars an awful lot of radiation would saturate the cluster - Not to mention the occasional supernova (I calculate about one every 750,000 years in the cluster) which would sterilize everything. Since evolution occurs on a lot slower time scale than the rate of supernovas, this alone would probably be enough to preclude the development of life.
I saw this back in April from our dark sky site. It was dark enough that O Cent was naked eye even on the horizon. O Cent was bright enough that it had a Red color to it.
Through the scope, it’s like a wall of stars even at lower powers.
As for the 750,000 years between supernovas, why so?
Full galaxies have them every 400 years or so. O Cent isn’t a full galaxy and I can see the chances being less. I was just curious about the reasoning.
From observing external galaxies, you get, on average, one approximately every 30 years in a galaxy about the size of ours. You can't see them in ours because most of our view of our own galaxy is obscured by dust and gas. Estimates on the size of our galaxy are 100 - 400 billion stars. I used 250,000,000,000 as an average size for calculation purposes. The cluster has about 10,000,000 stars ie. the cluster is 25,000 times smaller than our galaxy, so supernovae should occur 1/25000 as often, so 30 years times 25,000 = 750,000 years on average.
Isn’t that the end graphic for Buck Rogers ?
It sure was pretty 15,000 years ago. I wonder how much it’s changed since then.
Possibly on the moon of a gas giant with enough magnetosphere oompf to provide a safe envelope against supernovae waves? Or a binary with plenty of iron-radioactives in the liquid core to maintain a strong magnetosphere and push aside bad things. Who knows? The Universe is likely a very interesting place.
I wonder at the configuration of this GC and whether it has a strong x-ray source/black hole at its core as the larger actual galaxies do. Perhaps there is a mass threshold for black hole formation in large stellar groups and this cluster hasn’t reached it...
I was just curious. Makes good sense.
Current thought is that it is the core of a galaxy ripped apart by the Milky Way, not a Globular at all.
I have never heard of there being a black hole in the middle, but, there has to be something rather heavy in there to keep all those stars from flying away and keeping it’s rather round shape (actually it’s rather flattened, but...).
Then there is this article from 2008.
Apparently Hubble found one.
Or a General Products transperant #3 hull
Heh. I was thinking of the old Niven short story ‘At The Core’ when I saw the pic...
Wow! Thanks for that link!
I never cease to be amazed at what is out there.
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