Visibility of the Veil Nebula
One of the most beautiful emission nebula in the summer sky must be the Veil in Cygnus. Always a target for imagers, the advent of nebular filters has turned the Veil into a visual showpiece object for owners of large telescopes at star parties. They have also allowed it to be seen in small refractors, where the wider field of view of the modern short focal length instrument will often allow both eastern and western parts of the Veil to be seen together. Under a good sky parts of the Veil are also readily visible in binoculars without a filter, and some observers in the USA even claim it is naked eye with an OIII filter. The late Walter Scott Houston, in his Sky &Telescope column, reported that experienced observers had detected it naked eye through a UHC filter.
The Veil is the result of a supernova explosion some 100,000 years ago. It was first catalogued by William Herschel in 1784, who noted the bright eastern region NGC 6992 (John Herschel later observed an extension to this now known as NGC 6995) and the slighter fainter western region NGC 6960 located around the 4th magnitude foreground star 52 Cygni. Herschel classified them as Class V objects – very large nebulae.
Recent visual observations of the Veil sent to me have included the following from Owen Brazell – “Whilst playing with my new toy (Williams 80mm f6 APO) I decided to try for the Veil. Both parts were easy with the Lumicon OIII filter and a 22mm Panoptic eyepiece.” Owen wonders, as I do, just how small in aperture you can go and still see it. Is it really a naked eye object from the UK?
Neil Bone, also observing with an 80mm refractor for his new deep-sky book, reported – “I can confirm that this instrument will indeed pull out the eastern part, at least, of the Veil, especially with an OIII filter in place. In particular, the southern part of NGC 6992 was prominent, with a mag. +9 star just to its SW.”
Peter Hudson, observing from north Bedfordshire with his venerable 10×50 binoculars under good transparent skies noted – “I first tried for it with my 11×80 binoculars which I know reveal the eastern portion without a filter. It was easily visible. I then tried the 10x50s without a filter. With averted vision the ghostly arc of the eastern part could just be detected and having located it, was held with direct vision. There was no indication of the western part. If I did not know what I was looking for in the field of view I would probably have missed it. Knowing the field of view plus having transparent skies is probably the key”.
The Veil Nebula is a huge and complex area of nebulosity and contains parts to suit all apertures. When Cygnus reappears I’d be interested to know just what you can see, and if you find yourself under a really superb sky do see if it is a naked eye object. For an even greater challenge there is a central area to the Veil known as Pickering’s Triangular Wisp. According to The Night Sky Observers Guide, it is visible in a 14-inch telescope equipped with an OIII filter.