Error Analysis of the Light Curve Solution of Contact Binaries Based on the W-D Code

TL;DR

This study evaluates the accuracy of light curve solutions for contact binaries using Monte Carlo simulations and the Wilson-Devinney code, highlighting the impact of eclipsing type and third light on error margins.

Contribution

It introduces a Monte Carlo-based method to simultaneously assess systematic and random errors in contact binary light curve solutions, considering third light effects.

Findings

Systematic errors are generally smaller than random errors.

Photometric mass ratios are accurate within 1% for totally eclipsing binaries.

Faint third light can significantly increase solution errors.

Abstract

We use the idea of repeat measurement to determine the mean value and error of light curve solution parameters of contact binaries. Our simulation is realized by the Monte Carlo algorithm and Wilson-Devinney code. This method can obtain the systematic and random error simultaneously. Within our 48 models, the systematic errors are smaller than the random errors in most case. According to the numerical calculations, it is found that the relative errors of photometric mass ratios are less than 1% for totally eclipsing contact binaries, while they are generally between 10% and 20% for partly eclipsing ones. The effect of third light on the errors of photometric solution is also investigated. With a third light, these errors are close to 10% for totally eclipsing contact binaries. Specially, it is better to set the third light to zero in flux if that light is very faint (e.g., less than 1% contribution in luminosity), because such faint third light will bring big errors to the light curve solutions.