Messier 22 or M22, also known as NGC 6656, is an elliptical globular cluster of stars in the constellation Sagittarius, near the Galactic bulge region. It is one of the brightest globular clusters visible in the night sky. The brightest stars are around magnitude 11.
Image (click for full size):
Equipment
- Nikon D90 (Astro-Mod)
- Sky-Watcher Star Adventurer
- Sky-Watcher Tripod
- AF-S NIKKOR 500mm f/5.6
- Bahintov Mask
- Intervalometer
- Laptop
- All Sky Plate Solver
- Sharpcap
- Stellarium
Acquisition:
- ISO 800
- f/5.6
- Bortle 2-4
- Taken on 7/22/2021
- 183 light frames x 1 minute
- 150 bias frames
- 22 dark frames
- 100 flat frames
Processing:
- Calibrated subframes using WBPP
- Stacked using Normalize scale gradient
- crop out stacking artifacts
- extract luminance
- DBE
- Photometric color calibration
- EZ soft stretch
- Curves transformation
- HDR multiscale transform
- LRGB combination
Annotated Image:
