ИСТИНА

The UC gravitational lensing group is collaborating with other national and foreign groups about the construction, analysis and interpretation of light curves of gravitationally lensed quasars. The collaboration mainly focuses on the microlensing variability of such objects, and in this contribution, we present results from long-term optical monitorings of the quadruply-imaged quasar QSO 2237+0305ABCD (the Einstein Cross) and the doubly-imaged quasar SDSS J1339+1310AB. The former is an iconic object for microlensing studies, while the latter is a recently-discovered microlensing factory. We detect significant microlensing-induced variations in the light curves of both quasars, which allow us to discuss the structure of the accretion flow around their central supermassive black holes.