Planetary Nebulae (5 objects)

Go gently into that good night. When a sun-like star's nuclear fuel is exhausted, the core starts to shrink. The gravitational energy thus released heats both the core and the atmosphere even faster than the previously sedate nuclear furnace. The atmosphere is expelled, leaving a naked very hot tiny core (white dwarf). The intense UV from the hot core causes the atmosphere to glow in H-alpha (especially in an outer shell) and O-III (especially near in). Binary companions, strong magnetic fields, and equatorial dust lanes conspire to produce beautiful and convoluted shapes, seen very differently according to our viewing angle.

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Famous planetary nebula, the Helix in Aquarius. A pretty deep exposure (51 hrs) processed to bring out very faint outer features. H-alpha 31 hrs, OIII 20hrs. Mostly unbinned, some 2x2 binned, Mosaic of not-qute overlapping images from Aspen 16M and STL11000M. PlaneWave 20" CDK. Of great interest are the cometary knots seen as clumpy yellow-green streaks against the blue, radiating outward away from the blue-white central white dwarf. Notice the extremely faint chevron-like bow-wave shock fronts toward 9 o'clock., 10:30, and 11 o'clock. These structures average a flux of around just one photon per pixel per hour above background. There is a background galaxy clearly visible through the shocked material at 10:30, and several other tiny galaxies are visible in the image. North up. FOV approx half a degree.

Helix Planetary Nebula Narrowband Cometary Knot White Dwarf

Mike and Trish Berthon-Jones Astrophotography at Placidus Observatory

Planetary Nebulae (5 objects)