Search for MACHOs in the galactic dark matter

Machos (Massive Compact Halo Objects) might be a significant constituent of the dark matter that dominates the Milky Way. (Machos are a form of baryonic dark matter.) This article describes the experimental searches for Machos that exploit the gravitational microlens magnification of extragalactic stars. These surveys monitor millions of stars, in some cases every night, looking for magnification events. The early results from the surveys have yielded some spectacular events. It appears that Machos do comprise a significant fraction of the galactic dark matter. It also appears that the central bar of the Milky Way is very massive