The Witch Head Nebula, IC2118
2-Panel
Mosaic, 220 Minutes Total Exposure Time
Larger image at: 684x900 pixels
Reflection
nebula in Eridanus
Image
field of view: 1.5 x 2 degrees. (North is down)
Do
you see the witch's face? Her chin is at lower right, her lips are punctuated
with a red star, and her pointed nose is just above center. Rigel,
the suspected illuminator of this reflection nebula, is just outside the
top-right corner of the image. This nebula is a huge cloud of interstellar dust
particles that reflect the light of nearby stars. The particulate scattering of
light is more efficient at the shorter (blue) wavelengths of visible light, so
the camera records this image in ghostly blue. Wait... did I hear an evil
laugh?
This
image was selected for the Astronomy
Picture Of the Day, Feb. 27, 2001, was Santa
Barbara Instrument Group's "Image
of the Month for January, 2001" and was
published in Sky and Telescope Magazine, May
2001 issue, pages 141 & 143.
The
Witchhead image appears on Glinda's
Bubble Ancient Voices CD. 
This
astrophoto is also featured on the cover of The Universe and Multiple Reality by M.
R. Franks. 
The
book is available here at Amazon.com.
There is an interesting article written by Chris
Beckett for The
Newsletter of the Kitchener-Waterloo Center of the Royal Astronomical Society
of Canada that incorporates my
photo of this visually-elusive object. See
pages 7-8 of this article.
- Telescope:
Takahashi FSQ-106N 4-element fluorite refractor at f/5
- Zeiss
II German Equatorial Mount
- Santa
Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x
9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
- CFW8
color filter wheel with IR-blocking RGB dichroic
filters
Exposure Information:
- Date:
Saturday, January 20, 2001
- Location:
Joshua Tree National Park, CA
- Elevation:
Approx. 3500'
- OAT:
0°C. CCD temp: -30°C
- All
exposures were shot unbinned
- Total
exposure time: 3.7 hours (22 exposures of 10 minutes each)
- Exposures
(each of two panes in the mosaic):
|
Blue luminance |
9 exposures @ 10 minutes |
|
Red |
1 exposure @ 10 minutes |
|
Green |
1 exposure @ 10 minutes |
|
Blue |
(9 exposures @ 10 minutes, scaled) |
|
Total exposure time |
110 minutes, each of two panes |
E-mail
Gary at:
