(IAAC) blinking planetaries
Here is a "blinking planetary" in Hercules, all obs. in 13" f/5.6
IC 4593 faint, small, little elongated, stellar nucleus. Greenish at
all powers, central star most obvious at 165X. This planetary
"blinks", look at it, then use averted vision and the nebulosity will
appear and disappear. Sun Valley Parkway Seeing 5/10, transparency
6/10, easy at 150X, but needs power. 220X Pretty faint, small,
very little elongated 1.2 X 1 in PA 90, central star is obvious.
This planetary has been called the "while-eyed pea" and I see why,
the nebula is light green and the star is as white as Spica. Averted
vision makes it grow about twice its size and there is some very
faint outer nebulosity seen.
IC 4593 Cherry Rd. S=7, T=8, 13" 100X-just recognized as a disk,
pretty faint, very small, round, stellar nucleus; averted vision
makes the disk grow three times what it is with direct vision.
220X brings out the central star. 440X is the best view, round
light green disk with white central star.