Planetary Nebulas

Planetary Nebulas are the end evolutionary stage for stars with masses in the range of 0.8 to 8 solar masses.  As these stars age they deplete their store of  hydrogen and convert to burning helium which causes them to expand and become a Red Giant star.  Over time up to 70 percent of the stars mass can be lost as the thin outer atmosphere of the Red Giant is ejected outward by the solar wind generated by the star.  This ejected mass which we see as the “shell” of the nebula is illuminated by the ultraviolet radiation emitted by the star. This planetary nebula stage in the stars evolution is relatively short-lived in cosmic terms lasting perhaps only 100,000 years before the star eventually collapses to form a White Dwarf .  This will be the fate of our own Sun 5 billion years from now.

The most widely viewed Planetary Nebula is M57 the “Ring Nebula” located in the constellation of Lyra.  Easily viewed in small telescopes under dark skies  it has the appearance of a dim “smoke ring”. At the center of the ring lies a White Dwarf Star.
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Also known as the “Little dumbbell Nebula” due its resemblance to M27 (above).
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The Planetary Nebula Abell 12 is peeking out from behind the much closer double star Mu Orionis.
NGC 2392 earned its nickname “Eskimo Nebula” due to its resemblance to a face framed in a Parka Hood. Even in my rather modest 5 minute exposure the complexities due to the layers and subtle coloring of ejected gas from the 9th magnitude central star are evident.
A close-up view of NGC 1501 revealing some of the subtle internal detail within the nebula.
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A close-up and color inverted image of Planetary Nebula NGC 2438. The highlighted white dwarf central star, which was the progenitor of the nebula, is one of the hottest stars known. The other stars within the nebula are unrelated and are either in the foreground or shining though from behind.
NGC 7662, commonly referred to as the “Blue Snowball Nebula” is located in the constellation of Andromeda at a distance of ~5,600 Light Years, giving it a diameter of approximately 0.8 LY. The brightness of the central star varies from 12 to 16 magnitude.
The Saturn Nebula gets its name from its opposing lobes of ejected material which make it resemble the rings of Saturn viewed edge-on.
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NGC 7026 is a Planetary Nebula that also has the distinction of being labeled as a member of multiple star system BUP 9010! This system was cataloged by S.W. Burnham in 1879 who has the reputation of being a very keen observer, so his mistaking this nebula for a star is somewhat hard to explain.
The planetary nebula Vyssotsky 1-1 registers as a small blue disc in the photo above, but when one takes into account its great distance of 16,300 LY this would make the nebula more than 1.2 light years in diameter.
Even more distant than VY 1-1 above, HU 1-1 appears not much larger than the surrounding stars, subtending only 5 arc-seconds. Like VVY 1-1 only its pale blue color hints at its true identity. The photo above was taken with my 9.25 inch Schmidt-Cassegrain telescope. In larger telescopes its distinctive ring shape can be discerned.
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