Illuminating Hot Jupiters in caustic crossing

TL;DR

This paper explores the potential of gravitational microlensing caustic crossing events to detect Hot Jupiters orbiting stars, proposing a method that could identify about ten such planets over a decade of observations.

Contribution

It introduces a novel application of microlensing caustic crossing to detect Hot Jupiters, including simulation results and observational strategies for future surveys.

Findings

Optical depth for detection is approximately 10^-8.

Ten years of Galactic Bulge observations could detect around ten Hot Jupiters.

Infrared observations increase detection probability.

Abstract

In recent years a large number of Hot Jupiters orbiting in a very close orbit around the parent stars have been explored with the transit and doppler effect methods. Here in this work we study the gravitational microlensing effect of a binary lens on a parent star with a Hot Jupiter revolving around it. Caustic crossing of the planet makes enhancements on the light curve of the parent star in which the signature of the planet can be detected by high precision photometric observations. We use the inverse ray shooting method with tree code algorithm to generate the combined light curve of the parent star and the planet. In order to investigate the probability of observing the planet signal, we do a Monte-Carlo simulation and obtain the observational optical depth of $\tau \sim 10^{-8}$. We show that about ten years observations of Galactic Bulge with a network of telescopes will enable us detecting about ten Hot Jupiter with this method. Finally we show that the observation of the microlensing event in infra-red band will increase the probability for detection of the exo-planets.