SUPERCEDED - NGC 6822 - Barnard's Galaxy in Sagittarius
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NGC 6822 (aka IC 4895) is an irregular dwarf galaxy that is a member of our Local Group of Galaxies. The galaxy contains a mere 10 million stars - a very small number compared to the Milky Way Galaxy's estimated 400 billion stars. E.E. Barnard discovered the galaxy in 1881, earning this galaxy the distinction of being named "Barnard's Galaxy".
In this image, North is Up. This image is cropped to 71% of the original full frame.
Exposure Details |
Lens |
Celestron C-8 SCT with Celestron focal reducer |
Focal Length |
1260mm |
Focal Ratio |
f/6.3 |
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Mount |
Schaefer GEM - 7 1/2 Byers Gear |
Guiding |
80mm f/11 guidescope with PHD Guiding |
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Camera |
Canon 20Da |
Exposure |
90 subexposures of 300 seconds each at ISO 1600 - 7 1/2 hours total exposure |
Calibration |
30 darks, 30 flats, 30 bias |
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Date |
September 19, 20, and 21, 2011 |
Temperature |
62F on 9/19, 63F on 9/20 and 9/21 |
SQM Reading |
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Seeing |
5 of 5 on 9/19, 4 of 5 on 9/20 and 9/21 |
Location |
Pine Mountain Club, California |
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Software Used |
Images Plus 4.0 for camera control, calibration, and stacking. Images Plus 4.5 for digital development, adaptive Richardson-Lucy deconvolution, multiresolution sharpening, smoothing and noise reduction. Photoshop CS5 used for levels and curves, color correction, selective color, match color, high pass filter, star shrinking, lab color, saturation adjustments, screen mask invert, hdr toning, and smart sharpen. Gradient Xterminator for gradient removal. Carboni Tools for additional saturation adjustments, noise reduction, and smoothing. HLVG for additional color correction. |
Notes |
This is my 4th processing of this galaxy, and I used my DSLR-LLRGB workflow for the processing this time. I'm quite happy with the nice color saturation I was able achieve with this processing, and this processing represents a big improvement over my earlier attempts.
This image won 1st place in Astrophotogallery.org's September 2012 "Hard-Galaxy" category.
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