Just to add a 5 day later observation of the same thing -
This is from Bracknell - Thames valley UK combining 197 x 40s luminance frames (F4 12 inch telescope, 2.415 u pixel size AS1294MM) on the nights of 25 and 26 May 2023. The luminance was added to a colour image from last year (just thought it was nice to have it in colour although the new data are luminance only).
The SN seems to have remained at roughly a similar brightness since 21 May - maybe starting to fade?
The nearby star TYC 3852.1069-1 has an apparent magnitude of 12.62 according to a simbad database search on Aladin - and looks to be of comparable visible brightness to the supernova?
EDIT. trying to do this more correctly and using the Sharpcap Photometry tool on the linear data (see below) before stretching it is clear that at 40s both stars are ~ at saturation, Nevertheless based on the total rather than peak ADU numbers it looks as though SN2023ixf is perhaps ~ 0.75 magnitude (2X) brighter than TYC 385.1069-1. So a better guestimate of the supernova apparent magnitude would be ~ 11.75 rather than ~ 12.5?
At 33 ly distant the sun would have an apparent magnitude of + 4.83 (i.e at 10 parsecs - the definition of its absolute magnitude). SN2023ixf appears 2.512^(11.75-4.83) less bright this - i.e. some ~600 fold less bright. So SN2023ixf is shining with a similar brightness as would the sun at a distance of 33 x SQRT (600) = ~ 800 ly. So at 21 million light years, SN2023ixf is some 25000 X further out than this virtual equi-bright sun and thus must have a light output equivalent to more than ~ 700 million suns. Interesting to know what the correct figures turn out to be -- but this guestimate looks to be within the feasible range for Type II supernovae at least.
Tim
A somewhat trivial PS but I think it works out that were Betelgeuse which is at ~ 700 ly to go as a similar sized supernova it should shine at an apparent magnitude of about -11 as seen from Earth?
Attachments
SN_photometry.JPG (29.88 KiB) Viewed 6319 times
aaM101_SN2023ixf_annoated.JPG (75.81 KiB) Viewed 6348 times
Absolutly brilliant, I tried a couple of nights ago but a number of issues with the gear / guiding got me alongated stars and useless images. I could still see the supernova on a sub.
: Celestron CGX-L
: Astro-Physics 105 EDF f/5.8 + AP giant flattener
: ZWO ASI294MM Pro
: Montecatini Terme (PT) - ITALY
: Bortle 7
: 05/22/2023