IC 2149 is a small, bright
planetary nebula with something to offer in telescopes of all sizes.
At low magnification IC 2149 appears as just another 11th magnitude
star, although experienced observers may be able to recognize
something odd about it's color. At magnifications higher
than 120x a tiny, elongated disk becomes apparent, surrounding a
bright central star. At magnifications between 120x and 350x
look for a quite striking "blinking" effect as you switch
between viewing directly and with averted vision. When viewed
directly only the star is visible; when you look to the side a bit
(averted vision) the egg-shaped nebula pops into view.
Because the star tends
to dominate the view, using an OIII filter can be a great help
because it dims the star nearly to invisibility against the
background of the nebula.
magnifications the nebula takes on a bar shape and in larger
apertures tiny extensions can be glimpsed off each end.
I observed this one
with my 18-inch f/4.5 and my log begins, "Pretty darned
97x: Only stands out as
a star of odd color.
270x: Fairly bright
disk with bright central star. A real blinker!
Direct vision shows only
the star, averted vision pops disk into view.
The star somewhat
dominates the view.
430x: A bar-shape
becomes apparent around the bright star. OIII: star
all but disappears.
The bar is flat on one long side and has a "bottle
nose" on at least
one end. Very cool! This one's a keeper.
The field in an 6-inch f/8 at
50x. North is down and east is to the right.