Horsead Nebula
Horsehead Nebula
Barnard 33 and IC434
Dark Nebula and Emission Nebula in Orion



B33: The Horsehead Nebula (B33) is a gas cloud which blocks the light from the bright red nebula (IC434) behind it; IC 434 is illuminated by Alnitak, the left-most star in Orion's belt. This object is about 1,500 light years from the Sun; the Horsehead itself is perhaps 3 light years in height.


Technical Information:

LLRGB: 75:30:30:48 (Luminance layer consisted of 5 fifteen minute images; R and G comprised of 2 fifteen minute images; B comprised of 2 twenty-four minute images). L images unbinned; R, G and B binned 2x2.

Equipment: 10" LX200 at f/12 (note that the image was reduced by 1/3 for posting, so the scale is equivalent to an f/8 image), and an SBIG ST-8E NABG camera/CFW-8 color filter wheel, guided by an SBIG AO-7 adaptive optics device, guiding at about 37 Hz for Lum.

Image Acquisition/Camera Control: CCDSoft V5.

Processing: All images imperfectly calibrated (darks and old flats) and registered in AIP4WIN. Images average combined in Ray Gralak's sigma reject program. Five iterations of Richardson-Lucy deconvolution applied in AIP4WIN. Iterative applications of curves and levels in Photoshop 6.0, followed by unsharp mask and selective gaussian blurs in Photoshop. Color combine performed in Photoshop 6.0. Final image smoothed in Neat Image.

Location: My yard in Redmond, Washington, elevation 500'.

Date: All images taken during the night of 1/7/03.

CCD Temperature: -25C

Moon Phase: Waxing Crescent

Seeing: 2.8 Arcsecond FWHM

Copyright 2003 Mark de Regt