M13 Globular Cluster in Hercules

These are the first actual subs worth keeping that I have taken with the new setup. I still have a lot of work to do fine tuning the rig, but this isn't too bad. On the other hand, I only used about 2/3 of the frames i shot for the stack.

M13 is made up of perhaps half a million stars, and like most globular clusters, is orbiting around the center of the Milky Way galaxy. It's a pretty spectacular sight-the area visible in this picture is about 2/3 the size of the full moon, and in dark skies can even be seen with the naked eye, if only just.This image has some pretty blobby stars, but it was borderline foggy conditions...visually, I couldn't make out a single star in the constellation containing this cluster. This is just a baseline to add future exposures to, and a test of some of the mods I've been making to my scope setup. Given the nature of the skies, I didn't even spend much time with PhotoShop trying to clarify this picture, beyond some iffy contrast enhancement, since the background was really not black at all in the master photo, but reddish gray due to the normal light pollution and the moon.

M13 was discovered by  Edmund Halley in 1714, and Messier added it to his catalog half a century later. You can imagine how this could have been mistaken for a comet. The globular clusters especially were of a concern to those early comet-obsessed astronomers, since they are perfectly identical to actual comets in all ways save two-they don't move, and they are actually miniature galaxies on their own, not just balls of ice and dirt. Messier, by the way, said that M13 was entirely nebulous, with no discernible stars...again, it shows just what they were able to learn and deduce with equipment much worse than what I have today.

Because their close proximity has drawn all the material together in the region, any dust and gas clouds were long ago turned into stars in the most globular clusters, so they generally have few if any younger stars. Indeed, most of them are full of stars that are even older than the Milky Way itself-as much as ten billion years old.

Back in 2007, during a brief period when I first tried to get some photos with my scope, this was the best image I got of M13. Actually, it's probably the best image I got of ANYTHING that year, and it shows just why I gave it up as a bad cause.  Of course, few things show the weakness in an astrophotography setup the way clusters do-they are made up entirely of point sources of light, and even the tiniest errors are obvious. The gaseous nebulae can still look beautiful even with some tracking problems-look back to my early Orion shots as an example.