Cometary Globule
CG4 in Puppis (AKA- the Hand of God)
Shot from Southern California!
To see
the faint detail in this image, adjust your monitor's brightness and contrast
to clearly show all 17 steps in this grayscale chart:
This
image is the result of my silly attempt at detecting this faint cometary globule that lies at -47 degree declination.
Inspired by David Malin's photograph of this
beautiful object, I attempted its detection from a local observing site in
Southern California even though it barely clears the southern horizon from
here.
This
image was shot at an elevation angle that varied between 3.5 and 8.8 degrees
(at peak altitude). The light from this faint nebula had to penetrate 7 to 13
air masses before reaching the telescope. The long atmospheric passage severely
attenuated the light (particularly at the shorter wavelengths) due to Raleigh scattering and absorption. Atmospheric
turbulence severely blurred the image, making the stars appear large and fuzzy
and robbing the nebula of its beautiful detail. The raw subexposures
exhibited severe additive and multiplicative gradients.
MaxIm DL and Photoshop helped somewhat in
patching up this image, but the adage "Garbage In/Garbage Out"
certainly applies here. At least my preoccupation with shooting this object has
been satisfied: now I can get on with the program!
Just
to the left of CG4 lies the Magnitude 14.5 edge-on spiral galaxy ESO257-19.
Exposure
Information: