Herschel 400 Objects

NGC 6826 "Blinking Planetary": Planetary Nebula (Cygnus) RA: 19h 44.8m / DEC: +50° 31'.5
Instrument: 10-inch Starfinder

NGC 6826 is located near the tip of Cygnus' western wing. 3.8 magnitude Iota (10) Cygni is positioned 2.6 degrees to the northwest. The sketch at left records a 190X view in my 10-inch Meade Starfinder Newtonian. NGC 6826 is centered. Even at high magnification, the planetary nebula's 25" diameter form looks tiny. The 10.6 magnitude central star is visible but almost lost within the 9.8 magnitude glow of the surrounding nebulosity. An 11th magnitude GSC star shines about 2' to the south. Thirty-six additional stars are scattered across the field.

This object has garnered the popular nickname, the Blinking Planetary. The source of this moniker is an interesting visual effect. Under poor observing conditions, the nebulosity surrounding the central star is visible only with averted vision. When looking directly at NGC 6826, only the central star is visible. When looking with averted vision, the nebulosity appears and washes out the central star. This produces a strange blinking effect at the eyepiece as your eye flits between the two modes.

However, the effect is lost under the dark, transparent skies of northern Arizona. The nebulosity is quite bright and readily seen under direct scrutiny. In fact, the central star is almost overwhelmed by the brightness of this feature. I wonder if in some circles NGC 6826 has earned the nickname, the non-blinking planetary.


NGC 6823 NGC 6830

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Revised: January 26, 2003 [WDF]