Gravitational Mesolensing And The Hunt For Exoplanets

When astronomers talk about methods for finding exoplanets the list is relatively short. There is the radial velocity, or ‘wobble’ technique, which senses the motion of a star around a common center-of-mass with its planets. There is the transit technique, employed with great success by NASA’s Kepler mission, and there are direct imaging and phase-photometry techniques – challenging observations that seek the light being actually emitted or reflected from a planet. And then there is gravitational microlensing, the chance magnification of the light from a distant star by the distortion in spacetime due to the mass of a foreground star and its planets – with distinctive ‘blips’ or cusps of brightness due to any worlds aligned close to the right place in the star’s lensing field.