NGC 6905 -- Planetary Nebula in Delphinus
The Caged Planetary Nebula
The small Planetary Nebula NGC 6905 goes by several names. The Blue Flash Nebula or the
Caged Spirit Nebula are the most often encountered. The common names reflect the visual
impression that the tiny nebula is bouncing between a triangle of 11th and 12th magnitude
nearby stars. At high power the optical illusion was easily repeated in the small refractor. The
nebula seemed to extend itself to the adjacent stars for split seconds before returning to its
spherical shape. To me it gave the impression of a wild animal caged against its will bouncing
off the walls of its cage in anger.
Outside of the illusion, I could not detect the blue color of NGC 6905 as reported in larger
telescopes. Nor could I make out any internal details of the planetary nebula. Never-the-less it
is an intriguing object. I could not help but wish to see the ghostly-mist creature free itself from
its stellar cage.
Caged Spirit Nebula are the most often encountered. The common names reflect the visual
impression that the tiny nebula is bouncing between a triangle of 11th and 12th magnitude
nearby stars. At high power the optical illusion was easily repeated in the small refractor. The
nebula seemed to extend itself to the adjacent stars for split seconds before returning to its
spherical shape. To me it gave the impression of a wild animal caged against its will bouncing
off the walls of its cage in anger.
Outside of the illusion, I could not detect the blue color of NGC 6905 as reported in larger
telescopes. Nor could I make out any internal details of the planetary nebula. Never-the-less it
is an intriguing object. I could not help but wish to see the ghostly-mist creature free itself from
its stellar cage.