SaratogaSkies Jim Solomon's Astropics

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NGC 7023 (Iris Nebula)

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: Celestron/Baader Multi Purpose Coma Corrector (MPCC)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 42 x 4min @ ISO 400
Total Exposure: 2hrs, 48min
Date: 10/29/2005 9:28:47 PST (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Neat Image: Noise reduction
  • Photoshop: Levels, cropping, JPG conversion

Image Description:

This is NGC 7023, aka the Iris Nebula, in the constellation of Cepheus. This is my first auto-dithered image, using an adaptation of GADFly, originally written by TG Tan. The transparency was pretty lousy the night this was shot, and removing the background gradient was quite a challenge. A higher-resolution image is also available. North is up.