NGC 6826

NGC 6826
Nebula

A Hubble Space Telescope (HST) image of NGC 6826.
Credit: HST/NASA/ESA.
Observation data: J2000 epoch
Right ascension 19h 44m 48.2s[1]
Declination +50° 31 30.3[1]
Distance ~2000 ly ly
Apparent magnitude (V) 8.8[2]
Apparent dimensions (V) 27 × 24[2]
Constellation Cygnus
Physical characteristics
Radius 0.22 x 0.20 ly[2] ly
Designations HD 186924, SAO 31951,[1] Caldwell 15

NGC 6826 (also known as Caldwell 15) is a planetary nebula located in the constellation Cygnus. It is commonly referred to as the "blinking planetary", although many other nebulae exhibit such "blinking". When viewed through a small telescope, the brightness of the central star overwhelms the eye when viewed directly, obscuring the surrounding nebula. However, it can be viewed well using averted vision, which causes it to "blink" in and out of view as the observer's eye wanders.

A distinctive feature of this nebula are the two bright patches on either side, which are known as Fast Low-Ionization Emission Regions, or FLIERS. They appear to be relatively young, moving outwards at supersonic speeds.[3]

See also

References

  1. 1 2 3 "SIMBAD Astronomical Database". Results for NGC 6826. Retrieved 2007-04-17.
  2. 1 2 3 "Stellar Scenes Image Collection". NGC 6826. Retrieved 2007-10-05.
  3. "astroimages.org". NGC 6826 : The Blinking Nebula. Retrieved 2007-10-05.
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