Mar 31, 2010

What Do 10 Million Stars Look Like?

-FUPPETS- has the answer. From the good people at NASA's Astronomy Picture of The Day, here is a very crisp telescopic image of the globular star cluster Omega Centauri (named NGC 5139). Click the image below to enlarge.

Globular star clusters are large groups of stars that orbit around the edges of galaxies. This particular one orbits around our Milky Way galaxy, along with hundreds of others. Omega Centauri is the brightest and most densely packed of all the known star clusters. One strange thing about this star cluster is that it is far older than the other star clusters, with an approximate age of 12 billion years. It is also so densely packed in it's center that the stars there are less than .1 light year apart. That is ridiculously close by outer space standards. Just for comparison, the closest detected star to our Sun is Proxima Centauri, a red dwarf star approximately 4.2 light years away. If you happened to live on a world orbiting a star near Omega Centauri's center, it is likely you would never experience night, or what Earthlings consider night. The vast amount of nearby stars would ensure that even at "nighttime" the sky would never go dark. It is possible that even individual stars would not be discernible, just a flat field of light in the sky at all times. -FUPPETS- wonders what kind of mythology a species would develop without nighttime stars and celestial objects to ponder?

The image below is a tight close-up of the core of Omega Centauri. Click image for a larger version.

Most scientists think that Omega Centauri exists as the end result of an old galaxy colliding with the Milky Way, and scientists reported in 2008 that they have apparently detected a mid-sized black hole at it's center, which would also point to a galactic collision in the distant past as the cause of it's creation. It is hard to imagine that something so massive, with over ten million stars in it, is just a dwarf companion to our own galaxy. The Milky Way is also just a medium sized galaxy. There are galaxies out there with ten times the number of stars that our galaxy has. It is just a mind-boggling number and quite a humbling thing to ponder.

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