A New Parameterization for Finding Solutions for Microlensing Exoplanet Light Curves

TL;DR

This paper introduces a novel parameterization method for gravitational microlensing exoplanet light curves, improving the efficiency and robustness of identifying all degenerate solutions in the analysis.

Contribution

It proposes two new parameters, k and h, that replace traditional parameters to better sample potential solutions and uncover degeneracies in microlensing data.

Findings

The parameters k and h effectively identify degenerate solutions.

Tests show improved sampling efficiency over traditional methods.

The new parameterization enhances analysis robustness.

Abstract

The gravitational microlensing method of discovering exoplanets and multi-star systems can produce degenerate solutions, some of which require in-depth analysis to uncover. We propose a new parameter space that can be used to sample potential solutions more efficiently and is more robust at finding all degenerate solutions. We identified two new parameters, k and h, that can be sampled in place of the mass ratios and separations of the systems under analysis to identify degenerate solutions. The parameter k is related to the size of the central caustic, $\Delta\xi_c$, while h is related to the distance of a point along the k contour from log(s)=0, where s is the projected planet-host separation. In this work, we present the characteristics of these parameters and the tests we conducted to prove their efficacy.