How Gravitational Microlensing Looks to an Observer

This animation illustrates two ways a gravitational microlensing event could look to an observer. At top is the way it could appear to a telescope able to resolve the features. The source star appears to move and distort as its light is warped by the closer lensing star and its planet. At bottom is a light curve showing the intensity of light from the event. As the two stars reach best alignment, the signal reaches its peak. The planet orbiting the lensing star is detectable as a brief change in brightness.