My Imaging
I hope everyone is not tired of seeing M101 and the supernova, but each of us really has to have a go at capturing this amazing sight. My own imaging started on May 24th, so about 6 days after the explosion, near magnitude 11, which is about the maximum brightness. My final image was on June 24th (too low in the sky once skies cleared again to image further, unfortunately).  I could not find a light curve that recent, but the decline in brightness has been very small up to early June anyway, where the supernova was still close to magnitude 11. In my images I did not notice a significant brightness change over the month. Due to my extreme light pollution at Bortle 8 (as well as local light sources) I imaged with my L-eNhance NB filter, which I find works well for me on galaxies. My final image is about 12 hours integration taken under reasonably clear conditions over 4 nights. Sadly, I had to throw out 3 nights of imaging, with too much smoke and moonlight, making those subs unusable.  Thus I am sadly short on integration for the fainter parts of M101, which I will remedy next year I hope. it will be interesting to see how bright the supernova is then. The position of the supernova SN2023ixf is just to the right of the HII region NGC 5461. Image B has the position of the supernova marked.

The Pinwheel Galaxy
The Pinwheel Galaxy (aka Messier 101 or NGC 5457) is a face-on spiral galaxy with a diameter of 170,000 light-years (about 1.5X our Milky Way) that is 21 million light-years distant from us.  It’s six major companion galaxies (NGC 5204, NGC 5474, NGC 5477, NGC 5585, UGC 8837 and UGC 9405) are likely responsible for creating its wonderful fully developed spiral arms, creating this beautiful Grand Design Spiral structure. Also due to the tidal forces from these companions, M101 is asymmetrical. These gravitational forces also compress interstellar hydrogen gas, which then triggers strong star formation activity in M101's spiral arms. And as a result there is a high population of H II regions, which often have  a high density of molecular hydrogen gas that compresses under its gravity to form new stars. There are nearly 13,000 H II regions cataloged in M101, and a number are large enough and bright enough to have their own NGC numbers, as you can see when you mouse over to see the plate solving.

Supernova SN2023ixf
It is probably not surprising then, that the supernova SN 2023ixf so close to the prominent HII region NGC 5461, within the same spiral arm. An HST study showed that there are three massive young star clusters in this H II region, where there are frequent supergiant stars, like the one that caused this supernova. The supernova was discovered on May 19th by the famous Japanese amateur astronomer Koichi Itagaki, who has found more supernovas than anyone else (There is a wonderful article in Science about him, though you will need access to a subscription to read it). Subsequently, it turned out another amateur had captured the onset on May 18th between 19:30 and 20:30 UT. And other amateur astronomers had captured it at 9 and 33 hours after the explosion, where it rose from magnitude 22 to 15! While it is still early to be sure, a potential progenitor 15-solar-mass red supergiant, that is buried in a circumstellar dust shell, has been identified. Of course, in fact the supernova exploded 21 million years ago. SN2023ixf is a Type 2 supernova, which means that it shows hydrogen in its spectrum. It also means that the cause of this supernova is core collapse. Very massive stars can reach a point where nuclear fusion can no longer prevent the core from collapsing due to its own gravity, which can result in the violent ejection of the star’s outer layers, resulting in a supernova. However, in some cases the star can collapse into a black hole or neutron star with little energy radiated.