Date Posted: 6/8/2025
Date Taken: Five nights, from 3/26 thru 5/6/2019
Scope: Planewave CDK 12.5 f/8, 2541mm
Camera: SBIG STL-11000 with Astrodon Tru-Balance E-Series Gen2 filters
Temp: -15C, -25C
Mount: Losmandy Titan
Guiding: On-axis via ONAG-XM and SX UltraStar at 2541mm. FocusLock real-time focus for focusing.
Exposure: LRGB 370:160:160:160 All subs 5 min. Luminance unbinned, RGB binned 2x2.

Calibrated and Stacked with CCDStack2; RGB combine and DDP with MaximDL. Processed with CS4.

Messier 94 is a facing spiral galaxy about 16 million light years distant in Canes Venatici. It sports a bright central region, and a much fainter outer ring. UV and IR observations reveal the outer ring is actually a complex structure of spiral arms. The reason for the outer ring is not clear; one possible cause would be gravitational interaction with a satellite galaxy some time in the past; another is gravitational distortions cause by the oval inner disk.

This is a partial reprocess of an older image to reduce stars and bring out the outer ring.