SaratogaSkies Jim Solomon's Astropics

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B33 (Horsehead Nebula)

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

Image Details:

Camera: SBIG ST-2000XM
Mount: Astro-Physics 1200GTO
Scope: TMB 152/1200 APO Refractor
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: Astrodon SII, Hα, OIII 6nm Filters
Effective Focal Length: 1200mm
Effective Focal Ratio: f/7.9
Exposure: {5 SII, 5 Hα, 5 OIII} × 32min @ -20°C
Total Exposure: 8hrs, 0min
Date: 2/7/2008 8:19 PM PST, 2/8/2008 7:20 PM PST (Start)
Location: Saratoga, CA, USA
Acquisition: CCD Commander
Focus: FocusMax
Dithering: CCD Commander
Guiding: Self Guided

Processing:

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

Image Description:

This is B33, aka, the “Horsehead Nebula”, a dark nebula silhouetted against the bright nebula IC 434 in the constellation of Orion. Compare this closeup with the true color, wide-field, DSLR image, which shows the Horsehead in context with the bright belt star, Alnitak.

Mousing off the image reveals a “Hubble Palette” narrowband image, with R:G:B = SII:Hα:OIII. Mouse-over the image to see the H-alpha only image in grayscale. A higher resolution image is also available. North is left.

 
NGC 6309 (Box Nebula)
SaratogaSkies Jim Solomon's Astropics

Search

Latest news

December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!

Links:

NGC 6309 (Box Nebula)

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: 25 x 1min @ ISO 3200
Total Exposure: 0hrs, 25min
Date: 7/5/2004, ~10:30pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None

Processing:

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

Image Description:

NGC 6309, the Box Nebula, is a planetary nebula in the constellation of Ophiuchus. It's a fairly dim target, having a mean surface brightness of only 11.0 (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. Only 25 of the 54 frames were useable. The rest showed severe smearing/trailing and had to be tossed. This is a crop of the full-size frame. North is up.