|
Exposure |
Ha 480 min.
(16 x 30 min. bin 1x1)
R,G & B 150 min.
(10 x 5 min. bin 1x1, Each)
Ha, Green & Blue are
mapped to RGB respectively. RGB data was overlaid to show the
vdB75 & IC 444 nebulae.
The second image is a
straight RGB composition.
Click
here for the narrow band color mapped
image.
Click here for the B & W Ha filtered
image. |
|
Software |
CCDSoft,
CCDStack, Photoshop CS w/ the Fits Liberator plugin, Noel Carboni's actions
and Russell Croman's GradientXTerminator
CCDStack to calibrate, register,
normalize, data reject & combine.
PhotoShop for color
combine &
non-linear stretching. |
|
Comment |
North is to the top.
On the right is IC
443, the Jellyfish Nebula. This is a Galactic supernova remnant, in the constellation
Gemini, that
occurred 8,000 years ago. It is one of the best studied cases of
supernova remnants, interacting with surrounding molecular clouds.
IC 443 spans about 65 light-years at an estimated distance of 4900
light-years.
The large expanse, to
the left and to the top of the image, is the emission nebula
Sh2-249... at a distance of 5200 light years. Because it was so
difficult to get good data with a red filter, I choose to use the Ha
data for the red channel.
Above center, and a
little to the right, is the bluish reflection nebula vdB75.
Just to the right and slightly up, from vdB75, a small white patch
is visible. This marks the center of the emission and/or reflection
nebula IC 444. The structure of IC 444 is much more evident in
the NB color mapped image. |
