Short-duration lensing events: II. Expectations and Protocols
  Ongoing microlensing observations by OGLE and MOA regularly identify and
conduct high-cadence sampling of lensing events with Einstein diameter crossing
time, tau_E, of 16 or fewer days. Events with estimated values of tau_E of one
to two days have been detected. Short duration events tend to be generated by
low-mass lenses or by lenses with high transverse velocities. We compute the
expected rates, demonstrate the expected ranges of parameters for lenses of
different mass, and develop a protocol for observing and modeling
short-duration events. Relatively minor additions to the procedures presently
used will increase the rate of planet discovery, and also discover or place
limits on the population of high-speed dim stars and stellar remnants in the
vicinity of the Sun.
