Sharpless Sh2-117 is an extensive HII-region in the constellation Cygnus, consisting of the North America Nebula (NGC 7000) and Pelican Nebula (IC 5070). The two nebula are visually divided by a dark band of dust comprising the Lynds dark nebula LDN 935.
LDN 935 actually lies at a distance of about 520 parsecs in front of Sh2-117.
The distances to the North America Nebula and the Pelican Nebula were controversial, because there are few precise methods for determining how far away an HII region lies. Until 2020, most astronomers accepted a value of 2,000 light years, though estimates ranged from 1,500 to 3,000 light years. But in 2020, the
Gaia astrometry spacecraft measured the distances to 395 stars lying within the HII region, giving the North America and Pelican nebulae a distance of 2,590 light years (795±25 parsecs).
Image acquisition & calibration by the staff at Deep Sky West Remote Observatory (
www.DeepSkyWest.com) using the Rokinon 135 system at DSW, New Mexico.
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