Microlensing of extended stellar sources

We investigate the feasibility of reconstructing the radial intensity profile of extended stellar sources by inverting their microlensed light curves. Using a simple, linear, limb darkening law as an illustration, we show that the intensity profile can be accurately determined, at least over the outer part of the stellar disc, with realistic light curve sampling and photometric errors. The principal requirement is that the impact parameter of the lens be less than or equal to the stellar radius. Thus, the analysis of microlensing events provides a powerful method for testing stellar atmosphere models.
4 pages LaTeX, to appear in New Astronomy Reviews - proceedings of the Oxford Workshop `Gravitational Lensing: Nature's Own Weighing Scales'. Uses elsart.cls. Paper also available at ftp://info.astro.gla.ac.uk/pub/martin/extended.ps