B33 - The Horsehead Nebula in Orion


Copyright 2009 Hap Griffin


Many of the areas of the sky appear dark in photographs not because of a lack of stars or glowing nebulae, but because of great lanes of obscuring dust between our vantage point and the objects beyond.  Such is the case with the Horsehead Nebula shown here...the most famous of all dark nebulae, and known as B33.  The dust is the remnant of an older generation of stars that long ago died in great nova and supernova blasts spreading the heavy elements they synthesized from primordial hydrogen during their lives back into space.  Spectral analysis reveals that the dust is composed largely of silicon, carbon and oxygen.  Here we see brand new stars being formed out of this material...one can be seen on the horse's "brow" and another near the tip of its "nose" glowing dimly in red light as they come to life.  These new star systems will likely eventually form terrestrial-type planets containing the heavy elements from the dust cloud from which they formed.

The Horsehead figure is actually a dynamic structure formed by the protrusion of a dense area of the larger dust cloud that can be seen at its base.  It lies in front of and obscures an area of red glowing hydrogen,  IC434.  The structure is huge...between 12,000 and 13,000 of our own solar systems could be spread out across it's "neck".  It is theorized that the Horsehead itself is a "Bok Globule" which will eventually break free from the main cloud and condense into individual stars. 

B33 lies at a distance of 1500 light years.

This image was captured through a narrowband filter admitting only a narrow slice of spectrum around the wavelength of glowing hydrogen.  Thus it is a monochrome (single color) image displayed as shades of grey.

Date/Location:    December 29, 2009     Griffin/Hunter Observatory    Bethune, SC
Camera: QSI 583wsg
Filters: Astrodon E Series Generation 2 HA 5nm
CCD Temperature: -20 C
Instrument:    Planewave CDK 12.5"  
Focal Ratio:   f/8
Mount: AP-1200
Guiding:    Auto via the QSI camera's built in Off-Axis Guider mirror and a Starlight Express Lodestar Guider
Conditions:    Clear and cold
Weather:    25 F, still
Exposure: 120 minutes total (6 x 20 minutes)
Capture: CCDAutopilot 4 w/ Maxim DL Camera Control, focused automatically w/ FocusMax   
Processing:    Frame calibrations, alignment and stacking with ImagesPlus v3.80.  Finishing in Photoshop CS4.