Globular Star Cluster Omega Centauri (NGC 5139) is by far the most impressive of all the globular star clusters.

It’s not exclusively a Southern Hemisphere object; it rises above the horizon in the southern US just enough that I was able to get a reasonably good shot of it a number of years ago. I tried again from the Florida Keys when I was at Winter Star Party last February, but there was some kind of dew issue and it just didn’t work out. But with it high in the sky here it’s one of those ‘strike while the iron is hot’ kind of images you’re gonna take when you’re down here.

One thing about the globulars is they are relatively quick and easy to shoot, and although processing later in the computer is different than doing an intricate nebula, it’s not terribly time consuming or complicated. Exposures are short, only 30 seconds in this case and it all went like clockwork and I had this thing bagged in a couple hours!

So here’s my 2024 version of Omega Centauri:

Omega Centauri, NGC 5139. Double click for a larger view…

While this thing looks just like all the globular clusters in the Milky Way (there are about 175 of them) just bigger, there’s a little more to the story that is currently unraveling.

Yes this is the biggest of all the globulars, but not by an incremental amount, it’s more than twice the size of most of the globulars with only one close second and that’s also a Southern Hemisphere resident: globular 47 Tucanae, lurking just at the edge of the Small Magellanic Cloud (SMC).

But there’s one thing about Omega that sets it apart from all the others: nestled in the center is a black hole! This is not a regular feature of globular star clusters and Omega is the only globular known to harbor one. So that’s curious…

However, there are some other objects that pretty much all have black holes in their centers: galaxies! Now, weighing in with nearly 10 million stars, it’s nowhere near the usual range of stars for galaxies which number in the billions, but there’s another oddity about it in that there are a lot of different types and ages of stars. Normal globulars have populations that are a lot more homogenous in both age and star color.

So there’s a lot of speculation that in fact, Omega Centauri is the remaining core of a dwarf galaxy that got too close to the Milky Way, who’s immense combined gravity was able to strip away all of the outer, more loosely held stars leaving only the compact, tightly held inner core of the galaxy intact, still in it’s orbit around the Milky Way center.