SaratogaSkies Jim Solomon's Astropics

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NGC 6369 (Little Ghost)

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Negative Projection (Barlowed)
Additional Optics: TeleVue 2x Barlow
Filter: None
Effective Focal Length: 2844mm
Effective Focal Ratio: f/14.2
Exposure: 53 x 1min @ ISO 3200
Total Exposure: 0hrs, 53min
Date: 7/6/2004, ~11:00pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None

Processing:

  • IRIS: Dark subtraction, flat field, registration, Kappa-Sigma stacking
  • Photoshop: Noise reduction, cropping, JPG conversion

Image Description:

NGC 6369, the Little Ghost, is a planetary nebula in the constellation of Ophiuchus. It's a fairly dim target, having a mean surface brightness of only 10.5 (Mag per square arc-second). As with the other images shot at this focal length, this magnification pushes the limits of my mount, especially without [auto]-guiding. I used Kappa-Sigma combining to create this image, which automatically rejects the "bad" data from smeared frames. This is a crop of the full-size image. North is up.