Messier 74 - The Phantom Galaxy
Date: November 16, 2020
Cosgrove’s Cosmos Catalog ➤#0063
Messier 74 - The Phantom Galaxy (click on image for full resolution via Astrobin.com)
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About the Target
Messier 74 - The Phantom Galaxy. Also known as NGC 628, M74 is a face-on spiral galaxy located in the constellation of Pisces and is 32 Million Light-Years from Earth. It has two well-defined spiral arms and is about 95,000 light-years across in size. It has a very low surface brightness, making it the second hardest object on the Messier List to observe visually (the first being M101), thus its name "The Phantom Galaxy". M74 is also noted for having three Supernova that has been identified: SN202ap, SN2003gd, and SN2013ej. SN2003gb is a type II supernova, with a known luminosity profile -allowing the distance to the galaxy to be determined.
The Annotated Image
An annotated image of M74 created by using Pixinsight’s ImageSolver and AnnotateImage Scripts.
The Location In the Sky
FreeStarChart.com: Constellation of Pisces with M74 marked by the yellow arrow.
About the Project
M74 was chosen mostly because it was a target of opportunity. It was at a convenient spot in the field of view formed by my tree line.
I took 123x150 second subs of this over the nights of November 12th & 14th. As it worked out, only 102 images were used as others were culled due to high-level cirrus clouds. Losing 25% of your hard-won frames is painful. But it got even more painful as I dug into the data more.
I ran into some strange noise patterns when I inspected the frames. Strange circular patterns that seemed to shift in color from center to edge. At first, I noticed some of this pattern in the flat frames (taken at the end of the night) so I processed the images without the flats. This did not remove the problem completely and I had new problems that the flat calibration process would normally remove.
SO I processed this image and was forced to “bury the defects in the black”. In other words - hide them by making the background sky much darker than it should be.
I consider this project a failure. I do not like the detail level and the feel of the final image.
Updated Comments 7-24-21 (as I Ioad this into the website):
I am committed to sharing my bad images as well as the good ones. This failure started when the night skies had very thin clouds and poor transparency. It continued when I saw the strange noise patterns. BTW - I did figure out what happened here - I was getting dew formation in the camera chamber inside the protective glass over the sensor! To correct it, I had to open the camera chamber, remove the desiccant tablets located there, and then recharge them by heating in a microwave oven. I then quickly reassembled the camera. This solved the problem. The camera was about 1.5 years old and clearly, it needed the recharge. But I look at this image and I really dislike the lack of sharp detail in the galaxy, the poor background sky quality, and the overall feeling of it being overprocessed. Images like these make me try twice as hard next time!
Not the Greatest Image, But……
It is better than the first time I tried to shoot M74 - back in October of 2019. HERE is a link to that post. While still needing work - the current image is a big step up from my first effort!
Here is a Side-by-Side Comparison:
The First version of M74 - taken in October of 2019. (Clock to zoom)
The Latest Version (click to zoom)
More Information
Wikipedia: Messier 74
The Sky Live: Messier 74
Capture Details
Light frames
The frame count is after culling was done
100 x 150 seconds, bin 1x1 @ -15C.
Total integration of 4.2 hours).
Cal Frames
45 Bias exposures
25 Dark exposures
Flats not used.
Capture Hardware
Scope: William Optics 132mm FLT F/7 APO
Guide Scope: Apterna 60mm
Camera: ZWO ASI294MC-Pro
Guide Camera: ZWO ASI290Mini
Focus Motor: Pegasus Astro Focus Cube 2
Field Rotator: Pegasus Astro Falcon
Mount: Ioptron CEM60
Polar Alignment: Ioptron Ipolar integrated alignment cameras
Software
Capture Software: PHD2 Guider, Sequence Generator Pro controller
Image Processing: Deepsky Stacker, Pixinsight, Photoshop, Coffee, extensive processing indecision and second-guessing, and much swearing…..
During the Summer of 2020, whilst stuck at home because of Covid I became very in improving the automation of the platform and achieving a more precise framing of the shots I made…