AP155 Refractor @ f7.1
Astro-Physics 1200GTO Mount
SBIG ST-11000M Class 2
SBIG Colour Filter FWL-8
MaxIm DL V4.53
7 + 11 September 2007.
Moon phase 0%, mag 4.0 sky.
= 5 x 600 sec 1x1 binned
G = 5 x
600 sec 1x1 binned
5 x 600 sec 1x1 binned
Lum 10 x 600 sec
CCD Temp @ -20°C
Raw Lum, RGB, Dark, Bias, Flat and
Flat Dark frames acquired in MaxIm.
Raw images reduced
& combined, normalised and Luminance master
deconvolved in CCDStack.
RGB colour master prepared in CCDStack using RGB filter colour ratios
LRGB combine, colour balancing and star processing in PS CS2
Details NGC 6992 & 6995
Also Known As
of the Veil nebula Complex
Part of the Sharpless 103 HII Region and the Cygnus Loop
RA and Dec
this image North is
top centre. The
image centre is at GSC 2688:1077
26m 32s J(Now)
Highest Altitude at This Site
1400 light years.
Size & Magnitude
The NGC 6992 field is approx 54 x 33 arcminutes
- ie ~ 2 x 1 Moon diameters. The image is a 1900 x 1200 crop of the
full resolution wide field image below.
The wide field image of Caldwell C33 is 112 x 77 arcminutes
What it is
These glowing filaments of interstellar
shocked gas are part of a larger spherical supernova remnant known as
the Cygnus Loop or the Veil Nebula -- expanding debris from a star which
exploded over 5,000 years ago. The other main components of the Cygnus
Loop are West of C33 and are called Pickerings Triangle and the
Witches Broom nebula