PSF model fitting to the sources in t1–t5 and Tr. For each pair of images, the left panel shows the original F606W band, with the source being fitted marked by a circle. In all panels, except in the bottom right, a brighter nearby source is subtracted before. In each case, the right panel shows the image after subtracting the point sources. For t3 and t4, the right panel also marks with a circle the original position if the source being subtracted.