Period variations of Algol-type eclipsing binaries AD And, TWCas and IV Cas

Abstract

We present new analysis of O − C diagrams variations of three Algol-type eclipsing binary stars AD And, TW Cas and IV Cas. We have used all published minima times (including visual and photographic) as well as new determined ones from our and SuperWasp observations. We determined orbital parameters of the 3 rd bodies in the systems with statistically significant errors, using our code based on genetic algorithms and Markov Chain Monte Carlo simulation. We confirmed multiple nature of AD And and triple-star model of TW Cas and we proposed quadruple-star model of IV Cas.

Investigating Period Variability Mechanisms in Eclipsing Binary Stars through Eclipsing Time Variation Analysis: A Case Study of TZ Bootis

“…Papageorgiou (2015) and Papageorgiou & Christopoulou (2015) suggested a fitting strategy for O − C analysis that incorporates optimization methods to explore the parameter space such as genetic algorithms (GAs;Holland 1975;Charbonneau 1995), heuristic scanning with parameter perturbation, the combination of Nelder-Mead downhill simplex and Levenberg-Marquardt (NMS-LM) algorithms, and Markov Chain Monte Carlo (MCMC)/Monte Carlo-based methods for error budget and parameter determination (Papageorgiou et al 2023). Parimucha et al (2018) and Gajdoš & Parimucha (2019) also proposed a fitting strategy that uses GA optimization followed by MCMC fitting for the O − C analysis of extrasolar planets and Algoltype EBs. We follow here the same fitting strategy enriched by new methods for global optimization.…”