Constraints on Jupiters from observations of Galactic Bulge microlensing events during 2000.

Abstract

We present observations of 8 Galactic Bulge microlensing events taken with the 1.0m JKT on La Palma during 2000 June and July. The JKT observing schedule was optimized using a prioritizing algorithm to automatically update the target list. For most of these events we have sampled the lightcurves at times where no information was available from the OGLE alert team. We assume a point-source point-lens (PSPL) model and perform a maximum likelihood fit to both our data and the OGLE data to constrain the event parameters of the fit.We then refit the data assuming a binary lens and proceed to calculate the probability of detecting planets with mass ratio q = 10−3. We have seen no clear signatures of planetary deviations on any of the 8 events and we quantify constraints on the presence of planetary companions to the lensing stars. For two well observed events, 2000BUL31 and 2000BUL33, our detection probabilities peak at 30% and 20% respectively for q = 10−3 and a RE for a 2 threshold value of 60.