My second integration of M31 with new data from last night. Baby steps!
When I decided to jump into this hobby, there were two targets I knew that I knew that I knew I wanted to start with: the Andromeda Galaxy and the Great Orion Nebula. Not only are they two of the brightest deep space “objects” in the night sky, but they are also quite large and fairly easy to reach with modest equipment. By the time I read some books, joined some clubs, did some research, and decided what to buy to start this journey, both these amazing targets had slipped away from my grasp for the summer. Only now, as we enter fall, are they coming back around and giving me a chance to gaze upon them and scoop up some photons. I think it is ridiculously cool that you can see these with your bare eyes on a clear night. Here is my first attempt at M42 working in collaboration with my AP buddy, Dave.
Dave an I collaborated on a couple of images last night by connecting his stock APS-C sensored DSLR to my EON 130 using the 2″ to 1.25″ step-down compression fitting on the Crayford focuser. The smaller sensor and closer proximity to the focuser on the scope almost eliminated the vignette issues I have with my full frame sensor and soon-to-be-removed filter spacing when I image with my camera. We were going to initially try for the Helix Nebula, but the ambient wash from the moonlight and skyglow was a but much for that target, so we switched to 5 minute exposures on Messier 33. The image below is the result of about 30 subs and an old (inaccurate for this shutter length) master dark that Dave had laying around.
The Triangulum Galaxy is a spiral galaxy approximately 3 million light-years from Earth in the constellation Triangulum. It is cataloged as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way, the Andromeda Galaxy and about 44 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye.
So the vignetting on the EON persists through the new imaging train. It’s just an overall bad combo with a full frame DSLR, but this is how we learn. I wanted to take a step back and get some good widefield data to lick my wounds before diving back into the prime focus challenges, so I went back to the side-by-side saddle and native EF mount to the 600mm f/4L IS for yesterday’s imaging session. The moon is waxing gibbous today at about 56% and growing fast, so when the weather broke yesterday afternoon, I knew I had to take advantage of the night. I headed up to the dark site in Huntsville (~52 miles one way for me) around 6:30pm and started setting up my gear. By the time my buddy, Dave, arrived at 8, I was polar aligned and ready for the stars to start popping out. I started with Andromeda (which I’ll process and share later tonight) and ended with the Seven Sisters. I wanted to image the Great Orion Nebula, but my camera battery AND my DC power pack driving my equatorial mount and dew heaters both were depleting quickly, so I didn’t make Orion’s rise before having to pack up. It was disappointing, but it did spur me to order a AC to DC adapter for all three equipment power points to arrive before the weekend should be fortunate enough to get another clear night. What a silly reason to end a gorgeous imaging night early!
My previous post shared the disappointing, noisy, and light lost attempt at M45 through my 130mm f/7 triplet. This is the do-over.
Messier 45 – more commonly known as Pleiades – is only about 444 light years from us… only. It is quite bright and clearly visible to the naked eye without any form of telescope or binoculars on a clear night. In Japanese, the star cluster is called Subaru… and happens to be the logo for the automotive manufacturer bearing it’s namesake.
When I get frustrated at my slow progress, it is always good to slow down and remind myself that the main reason I started this WordPress blog was to document that very progress. I more or less had written off this Messier 45 short integration for a laundry list of reasons, but my friend, Dave, reminded me that I could always go back and try to reprocess the data for a better result. I might not spend anymore time on this particular set of uncalibrated subs, but I think I got most of the visual ring out of the frame (pervasive artifact I’m dealing with at the moment) and you can make out what the target is supposed to be even if I lost a lot of the nifty nebulosity around the brightest stars.
The Pleiades, or Seven Sisters (Messier 45), is an open star cluster in the constellation of Taurus. Its nine brightest stars are made up of the sisters Sterope, Merope, Electra, Maia, Taygeta, Celaeno, and Alcyone, along with their parents Atlas and Pleione.
I forgot to mention in my last post that the night was cut short by smoke. I don’t know where the fire was or how large it was, but it devastated the seeing with atmospheric particulate. I had to cut the evening short due to this, but tried to get Messier 33, the Triangulum Galaxy, before it got too bad. I also took some subs of M45, but this weird optical issue made the Pleiades shots unusable. That will be great target to shoot again another time. The noise/vignette one-two punch strikes again! I am going to get this sorted. Seriously.
It has been nearly 3 months since my last imaging session. It feels weird to even type that, but it’s true. When you live in a red to white zone and don’t have any narrowband imaging capability, the nights of opportunity cycle with the moon phase and the cooperative (or not) weather. Between that and travel, I have successfully missed the last few decent windows of dark sky… and it shows.
When I first started reading about what steps I needed to take to venture into this hobby, it was last fall at the onset of winter. The targets fresh in my mind, from my vantage in North America, were Messier 31 – The Andromeda Galaxy and Messier 42 – The Great Nebula in Orion. By the time I actually got around to pulling the trigger on the purchase of an equatorial mount, they were gone for the season. I went out last night to the HAAS dark site and set up for what I thought was going to be an awesome and long night of clear skies and catching up on my learning process. We are just beginning to see the winter targets come back around, so I had to take a stab at our nearest galactic neighbor. I’m still very new at astrophotography and learning a lot every time I get out and image, but even with the little experience I have to date, I could tell I was really rusty getting started last night.
There are a few major issues I am trying to understand and work through with my equipment and process. The two largest ones at this point are the tremendous about of vignetting I get shooting a full frame 35mm sensor through my refractor and 1.25″ filter wheel prime focus set-up. I lose almost half the image (at the edges) due to loss of light. The other, and equally annoying, problem I have is noise. The images are so very noisy. Even with darks, I can’t seem to get a creamy smooth look and feel to my backgrounds. I’m sure some of this is my post-processing Fu, but a lot of it is shooting with an uncooled CMOS that wasn’t designed to be used for multi-minute exposures. Almost everything that I really want to shoot is hanging in the sky begging to go deep. Deep exposures are just something that is a tiny bit beyond my reach at the moment without sprinkling the salt and pepper all over my images. I seem to be doing a fair job at that already.
I haven’t been able to image in a while due to work travel and weather, but I did get to spend some time out at the HAS observatory this past weekend getting checked out to use the facility. I have been able to access the dark site (which is very nice) for some time now, but it’s about 110 miles (one way) from my house and takes a little planning and commitment to head out for a night… especially when the HAAS dark site is half the distance from me.
The HAS observatory has three tracking telescopes, but only one of them has go-to capability. They have a 12.5″ f/5 that is very easy to use and mounted such that most targets are viewable without any sort of step ladder to reach the eyepiece… even for short guys like me. They have another 12.5″ f/7 that is on extended loan from NASA. This scope is massive and the optical quality is quite amazing. It is also easy to operate, but due to the enormity of this behemoth, it requires a ladder to put the seeing-balls onto the eyepiece. Lastly, they have a 14″ SCT that is fork-mounted and connected to a computer running an older version of Software Bisque’s The Sky for control. All three scopes are very nice and housed in a permanent observatory building with a nine ton retractable metal roof.
I had the opportunity to get checked out for solo access to the observatory and had a great time learning the systems and procedures for operation. The 14″ is really the only scope set up for reasonable imaging and I don’t know how to tie an autoguider into that system, so I likely won’t be using it for imaging any time soon. It is nice to know that I can access the facility now for visual astronomy and learning with some fantastic tools.
Astronomy, and specifically astrophotography, is a journey in learning and developing skills. I’m not sure there is a way to truly master the observation and appreciation of a subject asymptotically infinite. My brain doesn’t compute on the scale of the universe. Like most technical hobbies, the tools and toys evolve with our skillset. I met a friendly fellow enthusiast on the field over the course of the evening that picked up astronomy nearly a decade and a half ago and had an impressive showing of astrophotography pr0n on display. I’ll just leave this here:
More practice on old data… this time cropped significantly.
It is a fairly common practice among astrophotographers (and especially newbies like me) to go back to old sets of subs and re-integrate the data for practice running through the different steps of post-processing workflow. Most of the time this is to try applying new skills or a shift in technique, but sometimes it’s just because the weather isn’t cooperating to allow new imaging to take place. I did realize this past week that I was leaving a step out of my PI workflow that may or may not make a difference in the linear FIT file I was working with from BatchPreProcessing to final image. That step was the Cosmetic Correction application to the integration step. This is intended to account for hot and cold pixels in the camera subs and remove them while stacking. I don’t believe this really helped me here because my camera is fairly new and the subs are literally the very first subs I ever captured of a deep space object. Nonetheless, I reworked this M81 and M82 data again. If you compare it to the original attempt I made back in May, this is an improvement in my opinion. I think the real answer for making it better is to go re-shoot this target and improve the RAWs with which I’m working.