First Detection of a Gravitational Microlensing Candidate toward the Small Magellanic Cloud

Abstract

We report the first discovery of a gravitational microlensing candidate toward a new population of source stars, the Small Magellanic Cloud (SMC). The candidate event's light curve shows no variation for 3 yr before an upward excursion lasting ∼217 days that peaks around 1997 January 11 at a magnification of ∼2.1. Microlensing events toward the Large Magellanic Cloud and the Galactic bulge have allowed important conclusions to be reached on the stellar and dark matter content of the Milky Way. The SMC gives a new line of sight through the Milky Way and is expected to prove useful in determining the flattening of the Galactic halo. © 1997. The American Astronomical Society. All rights reserved.