I've been observing SN 2013dy for some time now and I notice that my measurements are diverging from what others are reporting. I seem to get about 0.5 mag (V) brighter than the others. I never prejudge my measurements against others but a red flag goes up when I see such divergence and I go back to check each measurement. In this case I can't find anything wrong so would ask for advice on where to look next.
I use VPHOT and have been careful (I think) to set the aperture snugly around the target and to avoid the nebulosity of the galaxy in the sky annulus. It seems to me that should excess nebulosity get into the sky annulus it would make the sky appear brighter and, hence, the SN fainter? But I'm reading brighter.
Jim Roe [ROE]