The Omega Glory

No, this isn't a post about the terrible Star Trek episode with the same name (I haven't blogged about Star Trek for quite some time now), but rather about the amazing globular star cluster known as Omega Centauri.

Last summer I blogged about the Globular Star Clusters of the Messier Catalog. In the post I mentioned that Omega Centauri is located too far south in the sky for Charles Messier to have seen it. The cluster barely makes it into the sky from my home, climbing just 9 degrees above the horizon. (I live at 33 degrees North, for anyone living further north, the cluster is even lower in the sky or not visible at all). Unfortunately a rather large hill completely blocks its view for me. 

Thankfully, I attended a star party in late April that had an unobstructed view of the southern sky and I was able to see this fine star cluster for the first time in years. It was also the first time I was able to catch it using my Unistellar eVscope2 and the view was impressive.

2-minute exposure of Omega Centauri

The cluster is amazing in every way. From dark skies it is visible without the use of optical aid from binoculars or a telescope. The cluster is 4 million times more massive than our Sun, making it the most massive of our Milky Way galaxy's globular star clusters. At its core the stars are so closely packed together that they are estimated to be just one tenth of a light year apart. Keep in mind that the closest star to our own Solar System is over 4 light years away. Imagine what the night sky would look like from a planet orbiting one of the stars within this cluster.

Omega Centauri may very well be the remnant of a smaller satellite galaxy that has been caught and disrupted by the Milky Way.

To put things into perspective compare the view above with that of another globular star cluster, Messier 13 the "great globular cluster in Hercules": 

This image of M13 was also taken with my eVscope, but when the cluster was high in the sky and with an exposure that was 10 times longer (20 minutes, instead of 2)! Don't get me wrong, M13 is a nice cluster, but it's not really "great" when compared to Omega Centauri. 

Why? Not only is Omega Centauri much more massive than M13 (M13 is only 500,000 times the mass of the Sun), but it is also closer to us. M13 is located around 22,000 light years from Earth, while Omega Centauri is 17,000. This closer distance and much greater number of stars make combine to make Omega Centauri truly glorious.