by Rod Pommier
Telescope/Mount: Celestron Compustar C14 with Astrophysics 0.75x focal reducer (f/8.25).
Camera: SBIG STL 11000M with Baader Planetarium H-alpha,R,G,B filters. SBIG AO-L adaptive optics at 3.0 Hz.
Exposures: H-alpha:R:G:B=300:60:60:60=8 hours total exposure. H-alpha sub-exposures=30 minutes, RBG sub-exposures=10 minutes.
Location: Pommier Observatory, Portland, OR, U.S.A.
Dates: 2012-08-22 through 2012-08-24.
Description: This hybrid Hydrogen-alphaRBG image shows the "Mexico" and "Gulf of Mexico" regions of NGC 7000, the North America Nebula in Cygnus. It is also known as Caldwell 20. The west coast of "Mexico" is the brightest region, also known as the Cygnus Wall. The Cygnus wall is the most active star forming region of the nebula. It is a highly energetic and ionized shock front caused by strong stellar winds forcing the bright hydrogen cloud into the adjacent colder dark hydrogen cloud to the left. As the cloud is compressed, the stellar winds continue to erode its edges, forming the billowing shapes along the front. This bright region provides stark contrast with the black Gulf of Mexico region, formed by dark gas and dust lanes. The edges of the dark cloud show globules, filaments and wisps of dust dramatically silhouetted against the glowing nebula behind. The distance to the North America Nebula is not precisely known. Deneb (Alpha Cygni) may be the star that is the source of stellar winds and ionization, which would place the nebula at a distance of approximately 1800 light-years.