M51 - The Whirlpool Galaxy 2020 version
Date: May 30, 2020
Cosgrove’s Cosmos Catalog ➤#0028
Messier 51 - The Whirlpool Galaxy (click to enlarge)
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About the Target
Messier 51, also know as NGC 5194 is more famously known as the Whirlpool Galaxy. It can be found in the constellation Canes Venatici and is estimated to be about 31 Million Light Years from Earth. M51 was the first galaxy to be classified as having a Spiral and is know o have a Seyfert 2 active galactic core.
Wikipedia provides some more background:
“What later became known as the Whirlpool Galaxy was discovered on October 13, 1773, by Charles Messier while hunting for objects that could confuse comet hunters, and was designated in Messier's catalogue as M51.[ Its companion galaxy, NGC 5195, was discovered in 1781 by Pierre Méchain, although it was not known whether it was interacting or merely another galaxy passing at a distance. In 1845, William Parsons, 3rd Earl of Rosse, employing a 72-inch (1.8 m) reflecting telescope at Birr Castle, Ireland, found that the Whirlpool possessed a spiral structure, the first "nebula" to be known to have one.[ These "spiral nebulae" were not recognized as galaxies until Edwin Hubble was able to observe Cepheid variables in some of these spiral nebulae, which provided evidence that they were so far away that they must be entirely separate galaxies even though they are seen close together.”
I always thought this galaxy had a pretty cool history - it really helped us to understand the scope of the known universe….
About the Project
Back in October 2019, I took my first image of this galaxy, but I learned a lot since then so I wanted to give it another try.
I set the equipment at 9 pm last night after some late-day rains and had a plan of shooting 100 two-minute exposures. I usually monitor the session from within the house via TeamViewer but for some reason, the wifi connection in the driveway was pretty bad and I kept losing it. I went outside and checked on it periodically and things *seemed* be going well. Around 1 am I went out and did a more careful check only to discover that my focus point had shifted and I had 60 images with star metrics suggesting my focus was off. ARGG! So I carefully refocused with a Bahtinov screen and got things started again. At 3 am I shut things down and closed up shop for the evening. I was disappointed at losing 60 frames but I figured I still had about 50 good frames to work with. Well, it turns out that some cloud patches moved through the area during the second batch of exposures and I ended up with only 35 usable frames out of 110 taken.
Ouch. Nothing is worse than losing frames that were hard fought for!
So I processed those this evening and even though the Signal-to-noise ratio was not as good as I was shooting for, the image was still a big improvement over my first one.
The Annotated Image
An annotated image of M51 created by using Pixinsight’s ImageSolver and AnnotateImage Scripts.
The Location in the Sky
IAU/Sky & Telescope Constellation Man of Canes Venatici - with M51 marked by the yellow arrow.
More Information
Wikipedia: Messier 51
HubbleSite.org: "X" STRUCTURE AT CORE OF WHIRLPOOL GALAXY (M51)
Capture Details
Light frames
35 x 120 seconds, bin 1x1 @ -15C, unity gain,
Total of 1.16 hours
Cal Frames
Not Recorded.
Capture Hardware
Scope: William Optics 132mm f/7 FLT APO Refractor
Focus Motor: Pegasus Astro Focus Cube 2
Guide Scope: Apterna 60mm Guidescope
Mount: Ioptron CEM 60
Tripod: Ioptron Tri-Pier
Camera: ZWO ASI294MC-Pro
Guide Camera: ZWO ASI290MM-Mini
Dew Strips: Dew-Not Heater strips for Main and Guide Scopes
Power Dist: Pegasus Astro Pocket Powerbox
USB Dist: Startech 8 slot USB 3.0 Hub
Polar Alignment Camera: Polemaster
Software
Capture Software: PHD2 Guider, Sequence Generator Pro controller
Image Processing: Pixinsight, Photoshop - assisted by Coffee, extensive processing indecision and second-guessing, editor regret and much swearing….
During August and September I was out shooting every clear night. I had learned a lot of things but I was also noticing several issues that were causing me problems as I did more imaging. I decided to do something to address those issues….