This is the Witch Head Nebula, so named because of its shape which takes on
the profile of a cackling witch's face even down to the sinister hooked nose
and pointy chin. The nebula is classed as a reflection nebula
reflecting the light from the blue super giant Rigel in Orion. There
is also a slight bit of emission nebulosity from hydrogen gas within the
cloud and again irradiated by Rigel that adds a red tint to the blue
reflected light giving the nebula its violet hue.
The nebula is very faint and large. This image spans approximately
2.75 degrees of sky or almost six full moon widths from top to bottom.
South is generally up in this image so this image is upside down as normally
seen in the night sky from the northern hemisphere. Rigel, the bright
blue star in the southwest corner of Orion is to the right of the nebula as
shown here while east of the nebula in the night sky. Rigel's solar
winds are "blowing" the gas and dust of the cloud into the profile of the
witches face and are also compressing the gases giving opportunities for
star birth within the gas cloud.
The nebula is believed to be a supernova remnant of a long dead super giant
star and lies in the constellation Eridanus, the River just west of Orion
AKA: IC 2118, Cederblad 41
Telescope: TMB130SS @ f/5.25
Camera: SBIG STL-6303E
Acquisition and Guiding: CCD Autopilot controlling Maxim DL
LRGB Combine Exposures:
Luminance - 12 x 600 Seconds, Bin 1x1, 2 hr
Red - 8x600 Seconds, Bin 1x1
Green - 8x600 Seconds, Bin 1x1
Blue - 8x600 Seconds, Bin 1x1
Ha - 17x1,200 Seconds, Bin 1x1 for nebula detail
CCDStack 2+: Calibration, registration and color
ImagesPlus: Digital Development.
Photoshop CS4: Luminance, color combine, levels, curves,
LAB color adjustment, high pass filter, sharpening
NeatImage: Noise reduction