First detection of a gravitational microlensing candidate towards the Small Magellanic Cloud

Abstract

We report the first discovery of a gravitational microlensing candidate towards a new population of source stars, the Small Magellanic Cloud (SMC). The candidate event's light curve shows no variation for 3 years before an upward excursion lasting $ \sim 217$ days that peaks around January 11, 1997 at a magnification of $ \sim 2.1$. Microlensing events towards 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.