The microlensing events in Q2237+0305A: No case against small masses/large sources

Abstract

It is demonstrated that the 1988-90 microlensing events in image A of Q2237+0305 reported by Racine (1992) do not exclude microlensing models with very low average mass, making the source radius larger than the projected Einstein radius $η_0$ (Refsdal and Stabell 1991, 1993). This is contrary to what has been claimed by Witt and Mao (1994). Since these events are the best resolved microlensing events recorded in Q2237+0305, further work should not exclude the possibility of a large source when interpreting lightcurve data.