On The Period Determination of ASAS Eclipsing Binaries

TL;DR

This study compares Lomb-Scargle and PDM algorithms for period determination of sparse ASAS eclipsing binary light curves, demonstrating PDM's superior performance for non-sinusoidal systems and improving period solutions for over half of the cases.

Contribution

It introduces a comparative analysis of FFT-based and non-FFT-based methods for period detection in sparse eclipsing binary data, highlighting PDM's advantages.

Findings

PDM outperforms Lomb-Scargle for non-sinusoidal eclipsing binaries.

Semi-automatic methods improve period solutions in 53% of cases.

Identified 4 objects for further detailed study.

Abstract

Variable stars, or particularly eclipsing binaries, are very essential astronomical occurrence. Surveys are the backbone of astronomy, and many discoveries of variable stars are the results of surveys. All-Sky Automated Survey (ASAS) is one of the observing projects whose ultimate goal is photometric monitoring of variable stars. Since its first light in 1997, ASAS has collected 50,099 variable stars, with 11,076 eclipsing binaries among them. In the present work we focus on the period determination of the eclipsing binaries. Since the number of data points in each ASAS eclipsing binary light curve is sparse, period determination of any system is a not straightforward process. For 30 samples of such systems we compare the implementation of Lomb-Scargle algorithm which is an Fast Fourier Transform (FFT) basis and Phase Dispersion Minimization (PDM) method which is non-FFT basis to determine their period. It is demonstrated that PDM gives better performance at handling eclipsing detached (ED) systems whose variability are non-sinusoidal. More over, using semi-automatic recipes, we get better period solution and satisfactorily improve 53% of the selected object's light curves, but failed against another 7% of selected objects. In addition, we also highlight 4 interesting objects for further investigation.