NGC 6992/5 - Veil Nebula Arc

The Veil Nebula is a large supernova remnant in the constellation Cygnus. The supernova which created the nebula occured between 5,000 and 8,000 years ago, and the remnant has since expanded to cover an area of approx. 3 degrees. Estimations for its distance range from 1,400 to 2,600 light years. The brightest sections, designated NGC 6992 and NGC 6995, forms the eastern part of the main loop. It features a filamentary structure which is visible in big telescopes and in this photograph. When finely resolved, some parts appear to be rope-like filaments, caused by thin shock waves viewed edge-on. The remnant's dominating emission line is Hα (red), but there is also some green [OIII] emission towards the eastern (left) edge. The Veil Nebula was discovered in 1784 by William Herschel.

NGC 6992/5 - Veil Nebula Arc, Wright-Newtonian CCD image.
NGC 6992/5 - Veil Nebula Arc, an enlargement of this CCD-image.

Exposure Data

Instrument: 9.5" f/4.9 Newtonian
F/stop: 5.6
Exposure: 7 x 10 min
Camera: QHY8pro
Offset/Gain/Temp: 111 / 51% / -20°C
Date: October 9, 2010
Exposure start: 23:38 MESZ
Location: Edelweißspitze, Salzburg
Conditions: Visual limiting magnitude 6.4 mag, SQM-L sky brightness 21.5 mag/arcsec². seeing 1.0" FWHM, temperature 3°C, no wind, no dew
Autoguider: Meade Pictor 216 XT, max. error: 1" (RA) / 1" (Dec)
Enhancement: Basic data reduction, combine, deconvolution, logarithmic curves, background flattening, noise filtering, local contrast enhancement, star size reduction
Notes: Photo taken during my stay at the Großglockner-Hochalpenstraße in October 2010. See an Observation Report of this event (in German).