An Etymological Dictionary of Astronomy and Astrophysics

The time during which a → microlensing event occurs. It is given by the equation t_E = R_E/v, where R_E is the → Einstein radius, v is the magnitude of the relative transverse velocity between source and lens projected onto the lens plane. The characteristic time-scale of → microlensing events is about 25 days.

See also: → Einstein; → time-scale.