F555W images from (a) 1998 December 27 and (b) 1998 December 29, along with (c) the difference after the 1998 December 29 image was scaled to give the same ﹩m_{u}﹩ as the 1998 December 27 image. The images have been smoothed with a ﹩2\times 2﹩ boxcar filter to suppress noise. Positive and negative contours are spaced every 0.75 mag from 21.0 mag arcsec⁻². Negative contours are dashed.