Example of difference images for FRB190608. Panels a–c: correspond to the images of each epoch of the FRB190608 observations (three epochs in total for this FRB). Panels d,e: difference images using the image of the last (3) and first (1) epoch as a template, respectively. The solid and dashed circles in all the panels represent the aperture radius of one and two times the FWHM, respectively, as reference, where FWHM = ∼2.3″. Our photometric analysis uses an aperture radius of two times the FWHM to set the non-detection limiting magnitudes. The red ellipse represents the uncertainty in the FRB position.