Tucked under the Big Bear's tail is the tiny constellation of Canes Venatici, Boötes' hunting dogs. For such a small constellation it might be accused of celestial gerrymandering by having its borders claim such deep sky masterpieces as M51 (Whirlpool galaxy) from Ursa Major and M3 from the herdsman.
Messier 3 is a wonderful globular boasting half a million suns packed into its perimeter. Even from Towson you can sweep up this dandy DSO as a fuzzy 6th magnitude star roughly midway between Arcturus and Cor Caroli (the α star of Canes Venatici). My 6" RV-6 Newtonian at medium magnification and averted vision shows a brighter core and some of the members of the cluster winking in and out with averted vision. The 10" Cyrus reflector exposes many more suns and begins to hint at the true majesty of this object.
When planets aren't around for imaging I will give the deep sky a go. In this regard I'm not very hard core, using my unmodified Canon EOS t6i rather than a dedicated unit, and I have not invested in things such as a field flattener that the more serious imager might do. I also do not currently have a guide camera, relying on a good polar alignment and shorter ~30 second shots to keep stars from trailing. I use a simple illuminated tracing pad to serve as light source for my flats. I have invested in a copy of PixInsight for processing, and will probably be plumbing the depths of its functionality for years to come. So when at the end of April we had a pleasant evening, a little chilly but with pretty good transparency, I rolled the mount out of the garage, attached the Vixen, and set off to see if I could get a nice scrapbook photo of the globular.
One of the things that I wanted to try out was my recently purchased Baader Moon & Skyglow filter to see if it could cut down on the nasty light pollution in my stacked image that I so often encounter when doing deep sky. The company claims "it darkens the spectral region which is particularly marked by street lamp light, which is the biggest contributor to the nightly Skyglow". The second thing I was interested to evaluate was BackyardEOS, a software package that allows you to automate a sequence of exposures taken with the camera. In the past I had turned on the camera's built in Wi-Fi and used the Canon app on my tablet to take the exposures. But that gets tedious fairly quickly, firing off an exposure every 20-30 seconds.
The time spent on polar alignment was worth it as the scope dutiful slewed over to Arcturus for a quick focus check with the Bahtinov mask in place. From there we slid up to M3 and began the session shortly after the passing of astronomical twilight. The BackyardEOS performed quite well as I set up a series of 30 second exposures over 15 minutes. At the end of each run I would check that the globular was positioned near center and that no star trailing was evident. After 6 such runs I then set about acquiring the dark and flat exposures.
Of course, collecting the data is only half the game. The stack in Deep Sky Stacker looked pretty good when I did an auto-stretch in PixInsight. The light pollution detritus was much reduced, so high marks for the Baader filter doing its job fending off the neighbors' lights. This time, in my search for a good PixInsight workflow, I followed along with a YouTube video made by Richard Bloch. It was one of the best I've watched so far, easy to follow along and enough rationale provided for why you are taking certain steps. It ended up helping me produce a pretty nice image of this cluster of suns that was the first faux comet entry that Messier himself is thought to have observed.
It is always satisfying to see your work improve, and I was happy to find that my small investment in the two new tools did help me in my desire to occasionally snatch a deep sky portrait from the driveway of my home.
