This is my first SHO image, and my impression is that the additional time to get the SII signal is really worth. The SII channel added to the Ha and OIII, that are the base for OSC photographers, makes the images richer and more colorful. I used two dual band filters, the first Ha+OIII, the second SII+Hb in conjunction with an OSC camera. The Hb signal is in my opinion useless, being just a weak replica of the Ha. A simple SII filter would suffice as additional one.
IC5070The Pelican Nebula (also known as IC 5070) is an H II region distant 1800 ly, and associated with the North America Nebula in Sh2-117 as visible
here. The gaseous contortions of this emission nebula bear a resemblance to a pelican, giving rise to its name. The Pelican Nebula is located nearby first magnitude star Deneb, and is divided from its more prominent neighbor, the North America Nebula, by a foreground molecular cloud filled with dark dust.
The Pelican is much studied because it has a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming cold gas to hot and causing an ionization front gradually to advance outward.
Particularly dense filaments of cold gas are seen to still remain, and among these are found two jets emitted from the Herbig–Haro object 555, visible in the middle of the picture. More on HH objects can be found
here.
Millions of years from now this nebula might no longer be known as the Pelican, as the balance and placement of stars and gas will leave something that appears completely different.
(Mostly excerpted by Wikipedia)
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