I previously did a high magnification image on Pickering's Triangle with my SCT. This time I collected the full Cygnus loop as a 4-panel mosaic with my APO refractor to try and get the entire nebula. I had some very nasty reflections in the data that were hard to get rid of with processing. This was in the standard Hubble Palette. The full image took me 30 different night of data collection over the summer. The image was processed with Pixinsight and was my first image using RC Astro NoiseXterminator instead of MureDenoise. This total data acquisition time for the image was 6 hours per filter - 18 hours per panel for 72 total hours.
The
Veil Nebula is a cloud of heated and
ionized gas and dust in the constellation
Cygnus.It constitutes the visible portions of the
Cygnus Loop, a
supernova remnant, many portions of which have acquired their own individual names and catalogue identifiers. The source
supernova was a star 20 times more massive than the
Sun which exploded between 10,000 and 20,000 years ago. At the time of explosion, the supernova would have appeared brighter than
Venus in the sky, and visible in daytime. The remnants have since expanded to cover an area of the sky roughly 3 degrees in diameter (about 6 times the diameter, and 36 times the area, of the full Moon). While previous distance estimates have ranged from 1200 to 5800
light-years, a recent determination of 2400 light-years is based on direct astrometric measurements. (The distance estimates affect also the estimates of size and age.)
The names
Veil Nebula,
Cirrus Nebula, and
Filamentary Nebula generally refer to all the visible structure of the remnant, or even to the entire loop itself. The structure is so large that several NGC numbers were assigned to various arcs of the nebula. There are three main visual components:
- The Western Veil (also known as Caldwell 34), consisting of NGC 6960 (the "Witch's Broom", Lacework Nebula, "Filamentary Nebula") near the foreground star 52 Cygni;
- The Eastern Veil (also known as Caldwell 33), whose brightest area is NGC 6992, trailing off farther south into NGC 6995 (together with NGC 6992 also known as "Network Nebula") and IC 1340; and
- Pickering's Triangle (or Pickering's Triangular Wisp), brightest at the north central edge of the loop, but visible in photographs continuing toward the central area of the loop.
NGC 6974 and
NGC 6979 are luminous knots in a fainter patch of nebulosity on the northern rim between NGC 6992 and Pickering's Triangle.
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