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Scope: C8 f/7.5, Location: Laguna Mountains, CA, 19 March 2010 (Lum and RGB) Camera: SBIG ST8300M, 16 March, 2009 (Ha) Camera: Artemis285
Exposure: 8 x 6 minutes (1x1 bin) 10 x 6 minutes (2x2 bin) Luminance exposures with IR block, 5 x8 minutes Ha exposures (1x1), 8 x 3 minutes RGB exposures (3x3).
Processing: Images were captured Artemis Capture (as FITs). Aligned/stacked and dark subtracted in Astroart with Sigma Combine. All channels were scaled and rough color balanced in Astroart. Central Gradient was removed on all channels in Astroart. Channels were co-registered in Astroart. The 6 minute IR block exposures were used for the main luminance construction with level adjustments and curves to bring out object features. LRGB combine was done in Photoshop. G2V factors applied to color channels. Background noise reduction was applied in Photoshop. Selective sharpening was applied to galaxy features. Final touches and color balance in Photoshop. Final Image size is approximately 3321x2508 (resized to 2400x1800).
North is up in this image. The image was guided for all exposures. M101, located in Ursa Major, is somewhat irregular in that the core appears to be off center in the spiral. Despite the apparent imbalance, M101 is considered a fine example of the "Grand Design" type of galaxy. M101 contains many gaseous knots in its arms as can be seen in this image. The H-Alpha filter exposures tend to highlight some of these knots. M101 is about 25 million light years distant from earth. This image replaces an earlier image that can be seen in the Archives here. Horizontal FOV is 44'.
Image center is approximately - Equatorial 2000: RA: 14h 03m 12s Dec: +54°20'58"