M101 - The Pinwheel Galaxy in
Ursa Major
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version revealing the extent of the faint galactic arms.
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full resolution version.
Copyright 2010 Hap Griffin
Date/Location:
March 19, 2010 Griffin/Hunter
Observatory Bethune, SC
One of my favorite astronomical objects...the beautiful Pinwheel Galaxy, known
as M101. Recognized as one of the finest examples of a classic spiral, it
actually is quite non-symmetrical with its core being considerably off-center.
It lies at a distance of 27 million light-years and is huge (as galaxies go), spanning 170,000 light years
across its diameter, nearly twice the size of our own Milky-Way galaxy. It
has a total luminosity of 30 billion suns.
Camera: QSI 583wsg
Filters: Astrodon E Series Generation 2 LRGB
CCD Temperature: -20 C
Instrument: Planewave CDK 12.5"
Focal Ratio: f/8
Mount: AP-1200
Guiding: Auto via the QSI camera's built in Off-Axis Guider
mirror and an SBIG ST-402 Guider
Conditions: Clear and cool
Weather: 52F - 35F, still
Exposure: 380 minutes total (23 x 10 minutes Luminance binned 1x1, 10 x 5 minutes each in RGB
binned 2x2)
Capture: CCDAutopilot 4 w/ Maxim DL 5.08 Camera Control, focused automatically w/ FocusMax
Processing: Frame calibrations, alignment and stacking with ImagesPlus v3.80.
Finishing in Photoshop CS4.