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M51, The Whirlpool Galaxy

M51, the Whirlpool Galaxy, is a classic face-on spiral galaxy in Canes Venatici.

To see the difference that more exposure makes in improving the signal-to-noise ratio, Click your mouse cursor in the image to see a comparison between a single 10-minute exposure and a stack of ten 10-minute exposures.

Companion galaxy NGC 5195 is seen to the left (north) of M51. It is interacting with M51.

Exposure Data
  • Lens: Astro-Physics 130EDT F/8 Triplet Apochromatic Refractor
  • F/stop: f/8
  • Exposure: Stack of ten 10-minute exposures (100 minutes total exposure)
  • Mount: Losmandy GM100EQ Polar-aligned tracking equatorial mount
  • Guiding: Autoguided SBIG ST-4
  • Camera: Canon EOS 20Da DSLR
  • Mode: Raw
  • ISO: 800
  • White Balance: Custom
  • In-Camera Noise Reduction: Off
  • Filter: None
  • Temp: 40F
  • Time Start 2:31 a.m. EDT
  • Date April 30, 2006
  • Location: DelMarVa Star Party, Tuckahoe State Park, MD
  • Calibration: Darks and Bias in Images Plus
  • Processing: Stacked in Images Plus. Color correction, image enhancement in Photoshop CS2

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