In the last post, M27: The Dumbbell, I wrote about a stars’ finite life. M27 is a planetary nebula, the result of a dying star of intermediate size. A massive star goes from star to red supergiant, followed by a supernova. A supernova remnant is the resulting structure from the explosion. The image below shows the life-cycle of a star. In the previous M27 post the planetary nebula was created because it was a sun-like star. A massive star follows the other path shown, resulting in a supernova and leaving behind a supernova remnant.
In the constellation Cygnus there is a large supernova remnant know as the Cygnus Loop. The structure is so large that multiple NGC numbers have been assigned to different arcs on the loop. The three main visual components are The Western Veil, The Eastern Veil, and Pickering’s Triangle. Combined, these are known as the Veil Nebula.
The Veil nebula was discovered in 1784 by William Herschel. The source of this supernova remnant was a star 20 times more massive than the sun. It exploded around 8,000 years ago, and is about 2,400 light years away. It is visible in a telescope using an OIII filter, since most the emission is Oxygen. Without an OIII filter it would be difficult to see. Fun fact – The 1974 movie Dark Star, a riveting space adventure where the crew of the scout ship Dark Star wander the universe to destroy unstable planets, chaos ensues en route to the Veil Nebula.
The Eastern Veil consists of NGC 6992, NGC 6995, and IC 1340. This is the portion of the supernova remnant that is the subject of my image. The Eastern Veil is not up high enough to photograph until around 2:30am in May. It took a couple weeks to get enough data to complete the final image. Since the majority of the emission is Oxygen I used narrowband filters to capture the emissions.
The final image has 14.5 hours exposure time. It was taken using a a ZWO ASI1600mm-Pro monochrome camera attached to a Canon 500mm f/4 camera lens. The setup mounted to a SkyWatcher EQ6r-Pro EQ mount to follow the rotation of the earth. Dark and flat frames were taken and all frames were loaded into PixInsight for stacking and editing. I’m looking forward to attempting an image of the full Veil Nebula in the coming months, but for now I’m satisfied with the Eastern Veil Nebula.
- SII: 54 images, 4.5 hours
- Ha: 76 images, 6.3 hours
- OIII: 44 images, 3.7 hours
ZWO ASI1600mm-Pro, Canon 500mm f/4 IS L II
SII – 4.5 hours, Ha – 6.3 hours, OIII – 3.7 hours
