https://nova.astrometry.net/image/11983681 during this bad weather im going through some of the stuff from last year. This was taken near opposition with a 10" f/5 Dobson and a 2.5 Barlow , hand guided. Given that I had to recenter several times I think I might actually have to derotate the images is that correct? What is the longest time one can get away without doing that?