W80: The NAN-Pelican Complex
The dark dust lane in the Galactic plane of our Orion-Cygnus spiral arm is also known as the “Great Cygnus Rift”. This structure of dark molecular clouds harbors many regions of nebulosity with active star formation, the largest nearby H-II regions being: the W80 in Cyg OB7 including the NAN-Pelican nebulae E of Deneb (aka Sh2-117), plus the CYG-X in Cyg OB 2/9 with the Butterfly nebula around Sadr (aka Sh2-108, IC1318 and LBN234).
I’ve studied and described these regions of the Milky Way previously in this thread:
- W80 (NAN-Pelican EN), Cyg OB7
with glass EP: https://www.cloudyni...eld/?p=8111018
with IIT: https://www.cloudyni...ield/?p=8736267
- Cyg-X (Butterfly EN)
Cyg OB2 with glass EP: https://www.cloudyni...ield/?p=8022468
Cyg OB9 with glass EP: https://www.cloudyni...ield/?p=8121768
Tonight (2019-08-24, 00:30-03:30 Loc DST, CEST UT+2) I’m out again for a look at the “Northern Trifid-Lagoon” nebulae, but being in the neighborhood of Deneb, who can resist another wide-field view of the NAN-Pelican... The North America (NGC 7000) and Pelican (IC 5070/67) nebulae form a single large H-II cloud in the W80 region, located at a distance of ~600 pc. The emission nebulosity in W80 is bifurcated by the dense molecular cloud L935, residing in the foreground at ~500 pc. The NAN-Pelican form the northern ionized arc of a large (partly hidden) H-I bubble, which on the southern edge includes the Cygnus Arc emission clouds: IC5068 A-B-C, just below the Pelican.
The North America Nebula is mainly ionized by the two hot stars: HD199579 (O6V) plus J205551.3+435225 (O5V), the latter being obscured (dimmed by 9.6m) in LDN 935. A couple of beautiful open clusters are easily observed in the NAN: Collinder 428 in the foreground at the E, and the 100 Myr old NGC 6997 behind the NAN towards the W (at ~690 pc). Also, up N in the NAN, I can see the small NGC 6993 background star cloud residing in the B 352 dark nebula (“The Egg in the Birds’ Nest”), and I can just glimpse the small asterism W of the Bird’s Nest known as NGC 6989.
The ionized molecular ridge towards the S part of the NAN (the “Cygnus Wall”) is easily seen, as is another brightly ionized bow of nebula up north, SE the “Birds’ Nest”. These shock fronts must have been pushed out by expanding H-I bubbles caused by stellar winds and explosions from hot young stars, -- but I have not been able to find any information on the specific origin of these features in the NAN. -- Maybe others know?
To be continued...
Edited by AllanDystrup, 28 August 2019 - 06:17 AM.