NGC 2403 (also known as Caldwell 7) is an intermediate spiral galaxy in the constellation Camelopardalis. It is an outlying member of the M81 Group and is approximately 9.65 million light-years distant [1].
In 2004 the supernova SN 2004dj was discovered. Remarkably, while the galaxy is over 9 M light-years from earth, the supernova is clearly visible in photographs (see [2] for example). I've marked what I believe is the supernova in revision B.
I've tried to photograph the galaxy before but am never happy with the result. It has lovely colors but structure is difficult to highlight and it is a temptation to over process it.
This image came from two beautiful nights that we had on February 28/March 1; the second was only about three hours before the clouds reappeared but the subs were very good so I combined them. Sadly, it means that the stars are less good. I've been tinkering with the Quattro all autumn and on the second day worked out how to collimate the focuser properly. So the optical train was changed for the second night and I didn't get the camera rotation exactly the same.
[1] https://en.wikipedia.org/wiki/NGC_2403
[2] https://www.rochesterastronomy.org/sn2004/n2403s1.jpg
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