Fr.: effet de microlentille
A type of → gravitational lens, where the foreground → lensing object is of low mass. Microlensing is used in the search for → dark matter inthe → Milky Way galaxy and its nearest neighbours, as well as for → extrasolar planets.
Fr.: dégénérescence des paramètres de l'effet de microlentille
Determining the three various parameters of a microlensing event (the lens-source relative parallax and proper motion, and the mass of the lens) from only one physical parameter (the event time scale). Currently the microlensing degeneracy affects the vast majority of events and makes any individual event impossible to interpret with certainty.