Sh2-188
This is one weird planetary nebula. The central star is way off center. It is the faint blue star left and a bit up from a yellow orange star that's quite obvious in a dark area above most of the HII filaments. The most common theory I find says that it is moving rapidly through the interstellar medium to the southeast (down and to the left). This motion creates a bow shock making the leading edge far brighter than the rest of the nebula partly from the shock and partly because it is pushed back nearer the ionizing central star. Don't confuse this one with the rather similar appearing Medusa planetary nebula. That one has the central star in the center where it belongs but otherwise looks much like this one. The Luminosity image was made from 2 30 minute H-alpha frames and 2 red frames as was the Red frame but the H-alpha was reduced to 30% in the red frame. Green was 2 10 minute shots plus 5% H-alpha and blue 2 10 minute frames + 10% H-alpha (using the two H-alpha frames). Taken with my 14" LX200R on a Paramount ME using my STL-11000XM CCD.
Rick
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