The MACHO Project Dark Matter Search

Abstract

We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (or Machos), using gravitational microlensing of background stars. This search uses a very large format CCD camera on the dedicated 1.27m telescope at Mt.~Stromlo, Australia, and has been taking data for almost 3 years. At present, we are in the midst of analyzing our second year data for 8 million stars in the Large Magellanic Cloud. We find more microlensing events than expected from known stellar populations suggesting that Machos are indeed present in the Galactic halo, but the observed microlensing rate toward the LMC is too small to allow for a halo dominated by sub-stellar Machos. Our observations of the Galactic bulge have also yielded substantially more microlensing events than anticipated including a number of exotic ``deviant" microlensing events. The implications of these results are discussed.

12 pages, uuencoded gzip compressed postscript (356 kb). Figures included. To appear in the Proceedings of the Astronomical Society of the Pacific Symposium on Clusters, Lensing, and the Future of the Universe