The Feasibility of Obtaining Finite Source Sizes from MACHO‐Type Microlensing Light Curves

Recent discussion of the effects of finite source size on high magnification microlensing events due to MACHOs motivates a study into the feasibility of observing such effects and extracting the source radius. Simulated observations are generated by adding Gaussian error to points sampled on theoretical microlensing light curves for a limb darkened, extended source. These simulated data sets are fitted in an attempt to see how well the fits extract the radius of the source. The source size can be fitted with reasonable accuracy only if the impact parameter of the event, $p$, is less than the stellar radius, $R_{star}$. It is possible to distinguish ``crossing'' events, ones where $p