Lunar Occultation of MACHOs

Cheongho Han, Vijay K. Narayanan, Andrew Gould
1996 Astrophysical Journal  
Lunar occultation can be used to measure the proper motions of some of the long time scale microlensing events, t_e 70 days, now being detected toward the Galactic bulge. The long events are difficult to explain within the context of standard models of the mass distribution and dynamics of the Galaxy. Han & Gould (1995b) have suggested that they may be due to a kinematically cold population near the Sun. To resolve the mass, distance, and velocity of individual events and so to determine their
more » ... to determine their nature, one must measure parallaxes and proper motions. For long events, parallaxes can be often obtained from ground-based measurements, but proper motions can only rarely be determined using conventional methods. Lunar occultations are therefore key to the understanding of the long events. We carry out realistic simulations to estimate the uncertainty of these measurements and show that proper motions could be measured for about one long event per year.
doi:10.1086/177086 fatcat:64um5v2v4fhy5p3hhaefgktxjq