The sequence of N − 1 group differences obtained from successive ramp fits to adjacent pairs of group reads, obtained from the ramp shown in Figure 2. The trail length of the asteroid in each group difference is shorter than its length in the full ramp fit, allowing one to integrate over fewer background pixels using shift-and-stack procedures. Group differencing has the additional benefit of increased temporal sampling of the ramp, allowing for the motion of a candidate asteroid to be confirmed within single JWST exposures. Time series of higher cadences than what is possible with the full ramp fits can also be constructed for both stationary and moving targets in the images. The dark black pixels in the center of the field star’s PSF are due to early saturation, such that successive group differences oversubtract the stellar core.