2004ApJ...609..166P

We analyze the Galactic bulge microlensing event MOA 2003-BLG-37. Although the Einstein timescale is relatively short, t_E=43days, the light curve displays deviations consistent with parallax effects due to the Earth's accelerated motion. We show that the χ² surface has four distinct local minima that are induced by the ``jerk-parallax'' degeneracy, with pairs of solutions having projected Einstein radii r{d5}_E=1.76 and 1.28 AU, respectively. This is the second event displaying such a degeneracy and the first toward the Galactic bulge. For both events, the jerk-parallax formalism accurately describes the offsets between the different solutions, giving hope that when extra solutions exist in future events they can easily be found. However, the morphologies of the χ² surfaces for the two events are quite different, implying that much remains to be understood about this degeneracy.