Description (Credit to SEDS):
M101 has a relatively close distance of about 22 million light years, which allows it to be studied in some detail. Recent evidence indicates that a close gravitational interaction with a neighboring galaxy created waves of high mass and condensed gas which continue to circle the galaxy. These waves compress existing gas and cause star formation. One result is that M101, also called the Pinwheel Galaxy, has several extremely bright star-forming regions (called HII regions) spread across its spiral arms. M101 is so large that its immense gravity distorts smaller nearby galaxies.
Dates Taken:
- 3/1/2011 through 3/10/2011
Equipment Used:
- TAK TOA-150
- Apogee U-16M
- Paramount ME
- Astrodon Gen2 LRGB filters
Exposures:
- L: 8*300s, 11*900s, 3.42h
- R: 14*300s, 16*900s, 5.17h
- G: 10*300s, 12*900s, 3.83h
- B: 9*300s, 17x900s, 5h
Totaling 17.42 hours
Processing:
CCDStack2:
1) Calibration with darks, flats, and bias frames
2) Bad pixel mapping
3) Image registration
4) Normalization
5) Data rejection (Clip Min/Max)
6) Mean combine
7) Hot/Cold Pixel rejection
8) Impute hot/cold pixels
9) Deconvolution
10) DDP
11) Color Combine
12) Produce scaled TIF
Photoshop CS2:
1) HDR combine
2) Color enhancement (Lab color approach)
3) Color enhancements with "Selective Color"
4) Noel Carboni’s Photoshop action for “local contrast enhancement”
5) Levels tweak
6) A small bit of extra deconvolution with FocusMagic
7) A very small amount of high pass filter edge contrasting