by Rod Pommier
Telescope/Mount: Celestron Compustar C14 with Astrophysics 0.75x focal reducer (f/8.3).
Camera: SBIG STL 11000M with Baader Planetarium H-alpha, L, R, G, and B filters.
Location: Pommier Observatory, Portland, OR, USA.
Dates: 2013-08-29 and 2011-08-01
H-alpha:L:R:G:B=420:205:35:35:35=12 hours 10 minutes total exposure
NGC 6960, also known as the Western Veil Nebula, the Witch's Broom Nebula, and Sharpless 103, is the remnant from a supernova which occurred about 10,000 years ago. It is the counterpart to the Eastern Veil Nebula, NGC 6992. Its amazing filamentary structure is thought to be due to compression of expanding shells of gas as they meet the resistance of the interstellar medium. However, the shells are so thin that, with few exceptions, we see them only where viewed exactly edge-on. The fact that much of what we see as "empty" space is filled with dark dust is evidenced by the fact that more background stars are visible below the nebula than above it. This is because the shock wave has swept the area below the nebula clear of the dust, allowing more background stars to shine through. The bright star, 52 Cygni, is a type K star and is actually a foreground object with no physically association with the nebula.
This is the hybrid of an LRGB image I took in 2011 combined with 7 hours of additional H-alpha data obtained in 2013 using the technique I described in my article in the October 2013 issue of Astronomy.