Veil Nebula... first process
Unfortunately I've not had chance to utilise the last few clear nights... work....! ;-(
PHOTO 1: So instead, I've processed the data of what I have so far.
First email (of four), shows a comparison between the Ha and OIII data on the 'Bridal Veil' section.
Hydrogen Alpha = 21x 600 sec sub exposures Oxygen III = 11x 600 sec sub exposures
Captured with Equinox Image (which I helped Beta-test on my old works MacBook Pro).
Calibrated with flat and dark frames in Nebulosity3.
Processed in Adobe PhotoShop CS5
PHOTO 2: Veil Nebula (EAST) NGC 6992, Caldwell 33, aka the Bridal Veil.
In above picture, I have added some more data to the previous mono Ha only posting....
A first full process of the data accumulated so far then:
Ha 21x 600sec - 7nm Baader Ha filter
OIII 11x 600sec - 8.5nm Baader OIII filter
SBIG 8Mp STF-8300M mono camera on the Takahashi FSQ-106ED + focal reducer (f/3.6).
Captured with Equinox Image and PHD on a MacBook Pro.
Used the 'Cannistra' technique for the build and synthetic green, see:
PHOTO 3: A close-up...
The Veil Nebula is a beautiful display of intertwining strands and folds of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the 'Cygnus Loop' (radio source W78, or Sharpless 103), a large but relatively faint supernova remnant. The source supernova exploded some 5,000 to 8,000 years ago, and the remnants have since expanded to cover an area roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full moon). The distance to the nebula is not precisely known, but Far Ultraviolet Spectroscopic Explorer (FUSE) data supports a distance of about 1,470 light-years.
The expelled remnants of this supernova can be seen strewn all about the region on long exposure photos, but it is the two brightest parts that are typically seen visually. The brighter, eastern portion can be spotted in binoculars from a dark site as a long curving hazy streak of light. I can confirm this as I've seen it from my B&B when I stop over in the week down in darkest Herefordshire using my cheapo, tripod mounted, 'Revelation' 15x70 binos!
Robert Burnham Jr. described the view of the eastern portion (NGC 6992) in six to eight-inch scopes as "looking like a miniature Milky Way in itself in the field. It appears as a faint curved arc like a ghostly white rainbow, over one degree in length."
In modern usage, 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.
Not shown here is the The Western Veil (also known as Caldwell 34), consisting of NGC 6960 (better known as the "Witch's Broom", "Finger of God",or "Filamentary Nebula"), near the foreground star 52 Cygni.
NGC 6979 is the fainter triangular nebulosity to the far right of this picture - 'Pickering's Triangle'. Pickering’s Triangle goes by a number of aliases, including Pickering’s Wedge, Fleming’s Triangular Wisp, and Simeis 3-188.
Pickering's Triangle is much fainter, and has no NGC number (though 6979 is occasionally used to refer to it). It was discovered photographically in 1904 by Williamina Fleming of the Harvard Observatory while examining photographic plates of the area (after the New General Catalogue had been published), but credit went to her boss, astronomer Edward Charles Pickering, the director of her observatory, as was the custom of the day.
The faint extension to upper left of NGC 6979 is NGC 6974. This one was separately cataloged by Lawrance Parsons in 1873.
NGC 6992 is actually only the upper part of the bright nebula to the left, with the lower part of the brighter area designated as NGC 6995. Both NGC 6992 and 6995 are named the Network Nebula. It was John Herschel who assigned it two different numbers in 1825.
The faint lower extension to that nebula is IC 1340. This one was cataloged by Safford in 1866.
As usual, needs more data (or perhaps I should not have pushed this quite so far!) Something to add to hopefully over the next month then - work, wife and weather permitting!
PHOTO 4: Another close-up.
Will try a different combine technique next... probably a straight Ha/OIII/OIII (R/G/B) in PhotoShop.