This galaxy is the third member of the Leo triplet. During the last nights I could image this with the Esprit120mm and the ASI183MM Pro. This intermediate result is L-filter 6hr36m of data processed in APP and cropped. Best seen by clicking on the image!
And below is the equivalent image taken with the Nikon D750 DSLR. I had a lot of noise in this 3hrs picture (36x300s), I suspect something went wrong with the dithering. The tidal stream is just visible.
When testing out the new ASI183MMPro CMOS camera, I pictured the galaxy NGC3628. This is a well-known galaxy, sometime called the ‘Hamburger’ galaxy, part of the Leo triplet.
When processing the image, I noticed this very faint trace abit to the south of the galaxy. I used the Minor Planet Checker to verify any known asteroids in this area, and I found only one a bith south of the very little galaxy underneath NGC3628 that I used the coordinates from (using SIMBAD and ALADIN).
I doubt the magnitude of 21,2. When I compare to a star nearby that has the same weight on my picture as the asteroid, that star is identified by the GAIA catalogue as magnitude 19,5. So my estimate for the asteroide, since it’s a moving object would be around 20.