D.1 UVIS Channel

The UVIS channel’s CCDs have no bright-object constraints. Overexposures on very bright targets do not have any adverse health and safety issues, nor do they affect subsequent exposures. As for any CCD, there can be some bleeding into adjacent rows and columns surrounding the bright object. Any charge bleeding is confined to one CCD and will not cross the chip gap. Diffraction spikes from very bright sources, of course, may cross the chip gap.

Charge bleeding is generally quite modest assuming the bright object is not itself the science target. From a scientific perspective, the largest problem with bright targets in the field is likely to arise from window or filter ghosts (see Section 6.5.3) or more rarely, scattered light (Section 6.10.6), effects that can be mitigated via dithering.