The Eastern Veil Nebula NGC6995/5
The nebula was discovered on 5 September 1784 by William Hershel. 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, and it exploded between 10,000 and 20,000 years ago. This Image shows objects of the Nebula on the eastern side of the loop. The Veil Nebula is expanding at a velocity of about 1.5 million kilometers per hour. Even though the nebula has a relatively bright integrated magnitude of 7, it is spread over so large an area that the surface brightness is quite low, so the nebula is notorious among astronomers as being difficult to see. However, an observer can see the nebula clearly in a telescope using an O-III astronomical filter isolating the wavelength of light from doubly ionized oxygen, as almost all light from this nebula is emitted at this wavelength. An 8-inch (200 mm) telescope equipped with an O-III filter shows the delicate lacework apparent in photographs. Smaller telescopes with an O-III filter can show the nebula as well, and some argue that it can be seen without any optical aid except an O-III filter held up to the eye. At the estimated distance from Earth of 2400 light-years, the entire Veil nebula (Eastern and Western combined) has a radius of 65 light-years (a diameter of 130 light-years). Some people can see an Image of a dog laying down in the sky.
This Image was captured over several evenings of clear skies starting on 5th September and completed early hours of the 12th September. Captured using Atik460 Mono Camera through a Skywatcher ED80pro Scope on EQ6 Mount. Comprised of 63 x 10 Minute Images using Narrowband Filters. (Ha Filter x 26, Oiii Filter x 22, Sii Filter x 10) These are then stacked using Deep Sky Stacker (Free Software) and Processed using Photoshop CS5. The Image are taken using a Mono (Black & White) Camera and mapped to the Hubble Pallet Colours using Photoshop to produce a colour image. This Pallet produces an image as if taken in colour via the Hubble Telescope (avoiding the Earths atmosphere) I will be imaging this Target again using standard Red/Green/Blue filters to show the difference.
The image left shows the stacked 26 x 10 minute exposure HA Images. The Lower Larger image shows the same 26 stacked picture before the detail is extracted using Levels and Curves adjustments in Photoshop. Nothing is falsely added to the image, all that Photoshop does is extracts the light that is captured in the image by the camera sensor so it is more visible. If you look you will you can see the stars are there, the process lightens these and brings the detail of the Nebula out.
Copyright on all images.