2023: Missouri – The Cygnus Loop

The Famous Cygnus Loop

The Veil Nebula Complex, also known as Sharpless2-103, is a supernova remnant located in the Cygnus constellation. It’s estimated that this star went supernova between 2,500 and 15,000 years ago. This enormous structure is almost 3 degrees across and covers a region in the sky six times the size of the full Moon. To capture the best image of it, the optimal time is during the Summer months when it remains high in the sky at night. The Cygnus Loop is situated next to one of the “swan’s wings” in the Cygnus constellation, and it’s 2,600 light-years away from the Milky Way Galaxy’s plane. Supernova remnants like this one play a significant role in stellar evolution by enriching space with heavy elements and triggering new star formation by compressing interstellar gas.

Observing Details

Object Designation NGC 6960 (The Western Veil Nebula) | NGC 6992 (The Eastern Veil Nebula) | NGC 6995 (The Bat Nebula)  | NGC 6960 (The Witch’s Broom Nebula and NGC 6979/NGC 6974 (Pickering’s Triangle).

The object in question can be found in the Constellation of Cygnus and is classified as an Emission Nebula. With a magnitude of 7, it is located 2600 light years away and was discovered by William Herschel in 1784. I started taking pictures at 8:17 p.m. and finished at 3:47 a.m.

About the Location

I heard that there’s a Bortle Scale Class 3 sky near Danville Conservation Area, which is a Class 4 sky. I’m interested in visiting this location to potentially take some photos. I reached out to the Central Missouri Amateur Astronomers in Columbia, MO, and they provided me with information on the area. During the third quarter moon phase in September, I went to Whetstone Creek Conservation Area in Williamsburg, MO to check it out.

When I arrived near sundown, about 15% of the sky had clouds, which started dispersing around 7:30 p.m. For the night seeing was good with FWHM between 70-89%, with wind speeds of <4mph, temperature reading of 55, humidity: 64%, and dew point: 59°F.

Equipment used

The imaging telescope was the RedCat 51, with the ASI2600, mounted to the ZWO AM5 and the ZWO TC40 tripod. I imaged in narrowband to isolate the hydrogen, oxygen, and sulfur wavelengths; the filter of choice was the Antlia 5nm Dualband Guiding.  For electronically assisted astro imaging, I find the ASIAIR smart wifi device a joy to use,  it’s a mini Raspberry Pi computer that you can connect to your phone or tablet via WiFi, giving you control over all of the imaging devices. I did all the post-processing using the software: Adobe Lightroom, Adobe Photoshop, and Pixinsight.

Acquisition details

RA: 20h 45m 38s and DEC: +30° 42′ 30″

Pixel Scale: 3.76μm, as the seeing was good, I went with a 1 x1 Bin, total exposure time of 6 hours and 45 minutes, which gave me 67 lights frames, which I then calibrated with 60 dark frames, 60 dark flats, and 50 flats frames. The gain was 100 and the camera was cooled -10° F.  The average moon phase was a waning crescent, the moon was 26.65 days old and 7.19% illuminated with a tilt of -4.543°. The approximate distance from Earth to the moon is 406,190.03 km and the moon sign is Leo.

Post Processing Workflow

• Stack the 67 frames in Pixinsight Weighted Batch Pre Process.
• Then drizzle the images (Drizzle is a statistical process; it gets better the more frames you use, but requires a reasonable minimum number of frames to work properly.)
• Make minimal color corrections.
• Crop it needed.
• DynamicBackgroundExtraction, often referred to as DBE, is one of the two primary tools PixInsight offers for identifying and removing these unwanted gradients.
•  Star Size Reduction and Detail Enhancements.
• Reduce the noise in the Linear data.
• Switching to Non-Linear: The way to stretch data.
• Remove any green color-cast pixels from the image
• Correct any Magenta stars.
• Curves Transformation and Color Masks to achieve the perfect hue and saturation for each color channel.
• Enhancing the dark areas in our image such as the interstellar dust lanes.
• Adding the stars back with PixelMath.
• Export the final image to Adobe Lightroom or Photoshop.
• In Adobe fix artifacts in bright stars.

The image below is the end result of the image capture, 6 hours, 45 minutes of data was stacked, and 2 hours of processing in Pixinsight and Lightroom.

Until the next adventure and thank you for stopping by!

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