Observatory night-shift staff watching a telescope all night handle transient alerts such as a possible very early supernova and must re-order the night's already-scheduled science tasks.
Today this relies mainly on staff manually watching control software all night, adjusting parameters and scheduling tasks, and manually re-planning the night when a sudden target appears.
Transients cannot be predicted in advance and their early brightness and spectra change fast, so slower discovery and follow-up leave less complete data; inserting a target also disrupts the existing schedule while staff still watch weather, equipment and target position.