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.