2025/11/19 by Kouzuma, Shinjirou
Decision Sciences · Mathematics · #Advanced Statistical Methods and Models #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Optimal Experimental Design Methods #Solar and Stellar Astrophysics (astro-ph.SR) #Statistical and numerical algorithms
paper · doi:10.48550/arxiv.2511.15537
openalex publication_date 2025/11/19 · openalex created_date 2025/11/23 · openalex updated_date 2026/07/28
We propose a simple method for estimating the fill-out factor of overcontact binary systems using the derivatives of light curves. We synthesized 74,431 sample light curves, covering the typical parameter space of overcontact binaries. On the basis of a recent study that proposed a new classification scheme using light curve derivatives up to the fourth order, the sample light curves were classified. Among the classified types, for systems exhibiting high mass ratios and high inclinations (i.e., SPf type), we found that the fill-out factor has a strong correlation with the time interval between two local extrema in the third derivatives of their light curves. An empirical formula to estimate the fill-out factor was derived using regression analysis for the identified correlation. Application to real overcontact binary data demonstrated that the proposed method is practical for obtaining reliable estimates of the fill-out factor and its associated uncertainties.