 This
planetary nebula is unique because some observers report it to
appear red in the eyepiece. Planetary nebulae typically appear
green or blue if they show any color at all. It has been
suggested that the red or pink color appears most obvious without a
filter and under direct vision. It has also been suggested
that the color visibility depends on the conditions as well as the
eye of the observer. The red hue may be most visible at the
outer edges.
The image on the right
was obtained with the Hubble Space Telescope. Note how the
reddish color is concentrated near the outer edge. In the
eyepiece, this edge isn't nearly as obvious. Also note the
intricate detail. This texture gives the nebula a unique
appearance in the eyepiece that is rather indescribable. IC
418 is quite small, so make sure to use as much magnification as the
conditions will permit.
After viewing it in my
6-inch, I wrote in my log, "Surprisingly high surface
brightness. Small, slightly elongated disk. Obvious at
135X." It turned out to be a very nice little object,
even for a six inch scope. The trick is to use as much
magnification as the conditions will permit to see this nice little
oval.
I later observed IC 418
in my 18-inch f/4.5. Here are my brief notes from my first
encounter:
Cool! Small,
bright. Bright central star. Oval. Gave
impression of intense color -- only I could not tell what color it
was!
This is the view in a
6" telescope at 50x. North is down and east is right.
More recently I
attempted to see the red hue in my 18-inch. At lower
magnification (94x - 166x) I was struck mostly by the blue color of
the central star. Higher magnification (430x) gave a much
better view of the surrounding nebulosity. As I had my first
look I twice had the distinct impression of a red or pink tinge, but
this impression went away with time. I spent about 30
minutes looking. I used various eye positions for averted
vision and looked at the nebula directly. There was a vague
impression of color, particularly near the outer edge, but as last
year I could not pin down what the color was.
What actually intrigued
me most was the impression of "texture" in the nebula.
It seemed smooth, yet somehow at the same time "lacy."
I couldn't figure out how to better describe the impression.
Then I saw the HST image for the first time! Now, I'm not
saying that I could observe the intricate detail directly, but its
presence was surely "felt" at the eyepiece.
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