NGC 6826 (Blinking Planetary Nebula) in Cygnus
The Blinking Planetary Nebula
The Planetary Nebula, NGC 6826, is small (less than half an arcminute) with a reasonably
bright magnitude 10.6 central star. When looking directly at it in a small telescope the star
can overwhelm the much dimmer nebula. The nebula proper, is more apparent when one
views it from an angle. This is do to the arrangement of the rods and cones in the human
eye. The nebula can appear and disappear depending on where the eye is looking in the
eyepiece – thus the common name of the Blinking Planetary.
Having said that, NGC 6826, is not that hard to see, especially if you add some
magnification (remember it is small). I do not find it necessary to use a narrowband
nebula filter even when viewing it from the light-polluted suburbs. Through the 6-inch
refractor at 243x the nebula no longer blinks even when looking directly at it.
The stunning blue-green color of the nebula with the bright-white central star is a
breath-taking sight.