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M97 Owl
ngc 40 Bow-Tie
ngc 1501 Oyster
ngc 1514 Crystal
ngc 2392 Eskimo
  ngc 6781.jpg -  NGC6781   Planetary Nebula with White Dwarf   distance: 2,500 ly     actual size: 2 ly     image size: 5'x5'  ST-8XME camera     Meade 10" LX200 scope @ 2000mm  (f/8)     AP900 mount 5.9 hour total exposure     LRGB = (70:65:130:90)     binned 1:2:2:2     (0.92" per pixel unbinned)   Guiding with ST-402XME camera on 2.8" Pronto scope @ 475mm (f/6.8)   This is an almost a perfect bubble of gas cast off by a single star that has died. The bubble continues to expand; it is approximately two light years across now. The distortion from a perfect sphere is due to UV radiation - energetic photons from nearby bright stars decomposing the gas bubble. Note the dim (magnitude 15.5) central white dwarf star.  This star now has about 60% of the mass of the Sun. It probably had 2 to 3 times this mass during most of its life  (while on the Main Sequence). It will steadily cool down and darken, eventually disappearing from view.   
ngc 6905 Blue Flash
ngc 7008 Fetus
ngc 7009 Saturn nebula
ngc 7293 Helix
ngc 7662 Blue Snowball

NGC6781
Planetary Nebula with White Dwarf

distance: 2,500 ly     actual size: 2 ly     image size: 5'x5'

ST-8XME camera     Meade 10" LX200 scope @ 2000mm (f/8)     AP900 mount
5.9 hour total exposure     LRGB = (70:65:130:90)     binned 1:2:2:2     (0.92" per pixel unbinned)
Guiding with ST-402XME camera on 2.8" Pronto scope @ 475mm (f/6.8)

This is an almost a perfect bubble of gas cast off by a single star that has died. The bubble continues to expand; it is approximately two light years across now. The distortion from a perfect sphere is due to UV radiation - energetic photons from nearby bright stars decomposing the gas bubble. Note the dim (magnitude 15.5) central white dwarf star. This star now has about 60% of the mass of the Sun. It probably had 2 to 3 times this mass during most of its life (while on the Main Sequence). It will steadily cool down and darken, eventually disappearing from view.

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