Transiting Planets Orbiting Source Stars in Microlensing Events

TL;DR

This paper explores how transiting planets around source stars can be detected during microlensing events, especially in dense stellar fields, by analyzing characteristic light curve deviations caused by planetary transits.

Contribution

It introduces a model for detecting transiting planets in microlensed source stars and estimates the low probability of such detections in individual events.

Findings

Detection probability per event is approximately 2×10^(-6).

Transit signals are more detectable near microlensing peak in dense fields.

Microlensing can enhance transit detection in crowded stellar environments.

Abstract

The phenomenon of microlensing has successfully been used to detect extrasolar planets. By observing characteristic, rare deviations in the gravitational microlensing light curve one can discover that a lens is a star--planet system. In this paper we consider an opposite case where the lens is a single star and the source has a transiting planetary companion. We have studied the light curve of a source star with transiting companion magnified during microlensing event. Our model shows that in dense stellar fields, in which blending is significant, the light drop generated by transits is greater near the maximum of microlensing, which makes it easier to detect. We derive the probability for the detection of a planetary transit in a microlensed source to be of 2*10^(-6) for an individual microlensing event.