NGC 6960 which is commonly known as the Veil Nebula or The Witch’s Broom is the western half of the Cygnus Loop. This is a large supernova remnant in the constellation of Cygnus. The supernova is from a star that is about 20 times larger than Sun. It’s estimated to have explored around 10,000 to 20,000 years ago. The Nebula is massive covering about 36 times the apparent area of the moon in the night sky. NGC6960 is about 2400 light-years away.
Analysis from the Hubble shows that the nebula has largely made up of Oxygen, Sulfur, and Hydrogen. The nebula also has other names like Finger of God, Lacework Nebula, or Filamentary Nebula.
Here you can see the area of the sky in Cygnus imaged.
Processing Info
I took this image at Cherry Springs, PA during the new moon weekend in May. It was a cloudy night with about two hours of clear sky. Between polar alignment and the rising sun, I was able to get an hour and a half of imaging.
I’m going to attempt this target again with better framing later in the season.
The following steps were performed in PixInsight:
- Channel Extraction
- Linear Fit
- Channel Combination
- Dynamic Background Extractor
- Backgrond Neutralization
- Photometric Color Calibration
- TGV Denoise
- Multiscale Median Transform
- Historgram Transformation
- SCNR (Removed Green)
- LRGB Combination
- Curves Transformation (x2 with a range mask. Inverted mask for the background and then non inverted for the target)
- HDR Multiscale Transform
- Multiscale Linear Transform
Acquisition Data
- Telescope: Explore Scientific FCD100 Series 127mm f/7.5 Carbon Fiber Triplet ED APO Refractor Telescope
- Camera: ZWO ASI2600MC Pro
- Guiding: ZWO Off-Axis Guider with Helical Focuser
- Guide Camera: ZWO ASI290MM Mini. Dithering every image at 1 pixel each time.
- Mount: iOptron CEM60
- Software: NINA for image acquisition. PixInsight used for stacking and editing. Imported to Photoshop for final touchup and watermarking.
- Other Accessories: AstroZap Dew Heater, Astro-Tech 2″ Flattener, MoonLite CFL 2.5″ Focuser, High Res Stepper Motor, V3 Controller, PrimaLuceLab Eagle 4s
- Filters: Optolong L-eXtreme (16 x 300s)
- Exposure Time: 1 hour 20 minutes -20°C
- Date: May 15, 2021
- Location: Cherry Springs State Park, Pennsylvania, USA
- GPS Coordinates: Lat. 41.6628445, Long. -77.8230494
- Bortle Dark-Sky Scale: 2
- Mean SQM: 21.17
- GPS Coordinates: Lat. 40.68187, Long. -74.89797
- Temperature: 46.4°F/8°C
- Avg. Moon age: 3.33 days
- Avg. Moon phase: 12.01%
- RA center: 20h 45′ 41″
- DEC center: +30° 41′ 20″
- Orientation: -111.14 degrees
- Field radius: 0.773 degrees
- Magnitude: 6.9
- Resolution: 3720 x 2330
Processing Info
It was almost a full moon and so bright when I captured this target. I had an Optolong L-eNhance 2″ filter which helped cut the moonlight. This tri-band narrowband filter worked like magic. When clear nights are so few and far in between, you have to use every opportunity to capture a target.
I originally had 45 frames at 300 sec each. I put them through the Blink tool in PixInsight and had to throw away one frame due to a dreaded satellite. Then the Subframe Selector Tool showed about six other frames with bloated stars with a high FWHM average. Most of them were due to haze and a sliver of clouds that came through during the night.
I stacked the 38 light frames along with 40 dark and flat frames.
The following processes were performed in PixInsight:
- Dynamic Crop
- Dynamic Background Extraction
- Automatic Background Extraction
- Background Neutralization
- Photometric Color Calibration
- Histogram Transformation
- Curves Transformation
- HDR Multiscale Transformation
- ACDNR (Noise Reduction)
- StarMask
Once I found what I liked, I saved the files and went to Photoshop, and ran Topaz AI DeNoise. This is an amazing plugin that works like magic.
Something is going on with either my back focus or tilt. The right side of the image has some stretched out stars which I’ll have to fix for the next time.
Here you can see the area of the sky in Cygnus imaged.
Acquisition Data
- Telescope: Explore Scientific ED127 Air-Spaced Triplet Apochromatic Refractor
- Camera: ASI071MC Pro
- Guide Scope: Orion ST80
- Guide Camera: ASI290MM Mini. Dithering every image at 1 pixel each time.
- Mount: iOptron CEM60
- Software: PixInsight used for stacking and editing.
- Other Accessories: AstroZap Dew Heater, Explore Scientific 2″ Field Flattener, ZWO ASIAIR, ZWO EAF Motorized Focuser.
- Filters: Optolong L-eNhance 2″
- Exposure Time: 3 hours 10 minutes (38 X 300 seconds). Gain 90, -10°C bin 1×1
- Exposure Start: 00:05
- Date: June 09, 2020
- Location: Voorhees State Park, NJ, United States
- GPS Coordinates: Lat. 40.68187, Long. -74.89797
- Temperature: 59°F/15°C
- Bortle Dark-Sky Scale: 4
- Astrometry.net job: 3591088
- Avg. Moon age: 17.63 Days
- Avg. Moon phase: 91.01%
- RA center: 20h 45′ 33″
- DEC center: +30° 43′ 33″
- Orientation: 95.920 degrees
- Field radius: 0.820 degrees
- Magnitude: 7.0
- Resolution: 4767 x 3131