Search for Extra-Solar Planets Through Monitoring Microlensing Events from Antarctica

Abstract

During the months when the galactic bulge is visible from the southern hemisphere, there are typically about 8 to 10 on-going microlensing events at any given time. If the lensing stars have planets around them, then the signature of the planets can be seen as sharp, extra peaks on the microlensing light curves. And if every lensing star has a Jupiter around it, then the probability of detecting an extra spike is of the order of 10%. Thus continuous and frequent monitoring of the on-going microlensing events, with a sampling interval of a few hours, provides a powerful new method to search for planets around lensing stars. Such monitoring programs are now being carried out using a network of 1-meter class telescopes situated at appropriately spaced longitudes in the southern hemisphere (for example, by PLANET collaboration). However, the galactic bulge is visible from the south pole throughout this period, and hence a single automated telescope at the south-pole can provide an efficient means of carrying out the monitoring program. Up to about 20 events can be monitored during a single 3-month season with a 1-meter telescope, potentially leading to the detection of two planetary signals. The telescope can also be used for several other research projects involving microlensing and variability of stars.