2.1928, 33.4259 The blue spot just below the red star. Shows up in the 4 single exposures from 17/09/2018 bright to 02/10/2-18 dim. Have checked on shows no record of a supernova in that area

Legacy Survey Sky Browser

Looks to be in the SDSS footprint when I checked, The object appears to be in SDSS. SDSS is an older survey (from the late 2000s to the early 2010s) and in the DECaLS/DESI Legacy Surveys, I see it is also there. Based upon the different bands the object has coincided, perhaps a distant galaxy or a foreground stellar object is the case on that one.

Nearby, high proper motion object (looks like an M/L transition dwarf).