Correlations Between Planetary Microlensing Parameters

TL;DR

This paper investigates how the parameters of planetary microlensing events influence light curve features and derives correlations to better understand parameter uncertainties, aiding in more accurate planetary characterization.

Contribution

It provides analytic and simulation-based correlations between microlensing parameters and light curve features, enhancing understanding of parameter dependencies.

Findings

Correlations between lensing parameters and light curve features are derived analytically.

Simulations confirm the applicability of these correlations to general planetary events.

Understanding these correlations helps in propagating uncertainties in planetary parameter estimation.

Abstract

Characterization of microlensing planets requires modeling of observed light curves including many parameters. Studying the dependency of the pattern of light curves on the lensing parameters and the correlations between the parameters is important to understand how the uncertainties of the planetary parameters are propagated from other parameters. In this paper, we show that despite the apparent complexity of the pattern of light curves of planetary lensing events, the correlations between the lensing parameters can be understood by studying how the parameters affect the characteristics of lensing light curves such as the height and width, the caustic-crossing time scale, and the location and duration of planetary perturbations. Based on analytic arguments about the dependency of light curve features on the parameters, we obtain the correlations for the two representative cases of planetary events. We also demonstrate the applicability of the correlations to general planetary events by actually obtaining the correlations from modelings of light curves produced by simulations.