SHORT TIME-SCALE MONITORING OF Q-2237+0305

Photometry in R and I' (similar to I) for the gravitational lens syste m Q 2237+0305 are presented in order to monitor the light curves of th e four quasar components over a period of hours to days; i.e., the tim e delay over which intrinsic brightness variations would be observed a ccording to theoretical models. No variations were found of any kind d uring a three-day period, but comparison of the R data with previously published observations provides new information on the microlensing o f component B reported in 1992. This component appears to have increas ed in brightness by at least 0.5 mag between 1991 March and July, and has decreased in brightness from the maximum by at least 0.15 mag by 1 992 mid-June. Light curves representing the history of the four compon ents are discussed in detail from which the rise time for component B, <720 days, and the event duration, >4 yr, are estimated.