I have already approached the NGC6946 Fireworks Galaxy, but only once – twelve years ago. I used a Canon 20D camera then, and a popular 150mm diameter Newtonian telescope. Now, after twelve years, my setup is technically more advanced, but, unfortunately, light pollution in my backyard is significantly worse 🙁 There were two decent nights at the end of September – decent means about 19.50 mag/arcsec2 at my location, so nothing extraordinary. But that was enough to capture NGC6946 with neighboring open cluster and also several more faint and distant targets.
NGC6946 is a face-on spiral galaxy located at the boundary between the constellations Cygnus and Cepheus. That region in the sky is fairly close to our Milky Way plane, so there is also a significant amount of dust. This dust is somehow visible in this image, but to capture it better, a much darker location is required. NGC6946 is about 25 mln light-years away, but it is heavily obscured by interstellar matter, so its brightness is dimmer than the distance would suggest. NGC6946 is also known by the fact, that ten supernovae have been observed in this galaxy in the 20th and early 21st century – that is the reason it was nicknamed Fireworks.
The Fireworks Galaxy was discovered by William Herschel on September 9, 1798. At the end of the XVIII century, Herschel and all others believed that object to be a gaseous nebula. William with his son John discovered about 5,000 nebulous objects during their observations. The true nature of galaxies was discovered and confirmed in the early 20th century.
NGC6939 open cluster is an old star cluster discovered by William Herschell as well. It’s ag was estimate to be between 1,0 and 1,3 billion years – and that is quite a lot for an open star cluster. It is not a very prominent target and to see it visually you need a 4 inches telescope and a dark sky far from city lights. NGC6939 is located about 4,000 light-years away from us and lies in the constellation of Cepheus already.
Besides the two main targets, there are also many faint fuzzies in the frame. If you take a closer look you can spot many small distant galaxies basically all around the image. The limiting magnitude of this photo is about 21mag, so it is not that deep, but still, some remote galaxies have been recorded.
The galaxy below is UGC 11557 – a low surface brightness galaxy. Not much data about this can be found on the Internet. It’s apparent diameter is two arc minutes.
There are several faint galaxies in this fragment of the image, and a patch of interstellar matter in the left upper part. The galaxy in the upper part is UGC11583 – another low surface brightness galaxy, but also a dwarf galaxy that is known to be a companion of NGC6946.
I love to “discover” such faint objects in the images I make. But under the light-polluted sky, it is hard to reach really deep (or far) into space especially if you would like to picture something other than narrowband nebulae.
Image technical data: Date: September 2024 Location: Nieborowice, Poland Telescope: TS Photoline 130/910 Corrector: TS FF/FR 0.8x Camera: QHY268M Mount: EQ6 Guiding: ASI290MM + Evoguide ED50 Exposure: LRGB 360:60:50:60 minutes Conditions: Bortle 6, transparency and seeing good