The North America Nebula (NGC 7000 or Caldwell 20) is an emission
nebula in the constellation Cygnus, close to Deneb (the tail of the swan and its brightest star). The shape of the nebula resembles that of the continent of North
America, complete with a prominent Gulf of Mexico.
On October 24, 1786, William Herschel observing
from Slough,
England, noted a “faint milky nebulosity scattered over this space, in some
places pretty bright.” [4] The
most prominent region was catalogued by his son John Herschel on
August 21, 1829. It was listed in the New General Catalogue as NGC 7000, where it
is described as a "faint, most extremely large, diffuse nebulosity.” [5]
In 1890, the pioneering German astrophotographer Max Wolf noticed
this nebula's characteristic shape on a long-exposure photograph, and dubbed it
the North America Nebula.[6]
In his study of nebulae on the Palomar Sky Survey plates in 1959,
American astronomer Stewart
Sharpless realised that the North America Nebula is part of the
same interstellar cloud of ionized hydrogen (H II region)
as the Pelican Nebula, separated by a dark band of
dust, and listed the two nebulae together in his second list of 313 bright
nebulae as Sh2-117. American astronomer Beverly T. Lynds catalogued the
obscuring dust cloud as L935 in her 1962 compilation of dark nebulae. Dutch
radio astronomer Gart Westerhout detected the HII region
Sh2-117 as a strong radio emitter, 3° across, and it appears as W80 in his 1958
catalogue of radio sources in the band of the Milky Way.[7]
The Pelican Nebula (also known as IC 5070 and IC 5067[1]) is an H II region associated with the North America Nebula in the constellation Cygnus. The gaseous contortions of this emission nebula bear a resemblance to a pelican, giving rise to its name.[1] The Pelican Nebula is located nearby first magnitude star Deneb, and is divided from its more prominent neighbour, the North America Nebula, by a foreground molecular cloud filled with dark dust.[2] Both are part of the larger H II region of Westerhout 40.[2]
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.[1] 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.
The image data was taken at Okie-Tex 2021 near Kenton, Oklahoma. The above image has NGC 7000, center, and IC5070 upper right, captured with a one shot color camera a StarLight Xpress SXVR M 25C. The image is made of 48 five-minute exposures using AstroArt 7 then calibrated, combined and processed using AstroArt8. The camera was mounted to a AstroTech AT72ED refractor. The guiding setup was a ZWO ASI120 attached to a SVBONY SV106 guide scope piggybacked on the AT72ED. The imaging setup was mounted on an Astro Physics AP900. Guiding software was PHD2.
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