ПИСЬМА В АСТРОНОМИЧЕСКИЙ ЖУРНАЛ, 2021, том 47, № 6, с. 428

The First Light Curve Solutions and Period Study of BQ Ari¹

E. M. Esmer⁶, O. Basturk⁶, E. Lashgari¹, J. Rahimi¹, Y. Alada ˘g⁷,

N. Aksaker^7,8, A. Boudesh¹, M. Ghanbarzadehchaleshtori¹,

A. Aky ¨uz^7,9, S. Modarres¹, A. Sojoudizadeh¹, M. Teke ¸s⁷, A. Solmaz¹⁰

¹The International Occultation Timing Association Middle East section, Iran

²Astronomy Department of the Raderon Lab., Burnaby, BC, Canada

³Canakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Physics,

17020, Canakkale, Turkey

⁴Canakkale Onsekiz Mart University, Astrophysics Research Center and Ulupınar Observatory,

17020, Canakkale, Turkey

⁵Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA

⁶Ankara University, Faculty of Science, Astronomy and Space Sciences Department,

TR-06100, Tandogan, Ankara, Turkey

⁷Space Science and Solar Energy Research and Application Center (UZAYMER), University of Cukurova,

01330, Adana, Turkey

⁸Adana Organised Industrial Zones Vocational School of Technical Science, University of Cukurova,

01410, Adana, Turkey

⁹Department of Physics, University of Cukurova,

01330, Adana, Turkey

¹⁰Space Science and Solar Energy Research and Application Center (UZAYMER), University of Cukurova,

01330, Adana, Turkey

Поступила в редакцию 13.02.2021 г.

После доработки 10.04.2021 г.; принята к публикации 13.05.2021 г.

The first analysis of the photometric observation in BVR filters of a W UMa type binary system BQ Ari

was performed. Light curve analysis was performed using Wilson-Devinney (W-D) code combined with a

Monte Carlo (MC) simulation to determine its photometric and geometric elements and their uncertainties.

These results show that BQ Ari is a contact binary system with a photometric mass ratio q = 0.548 ± 0.019,

a fillout factor f = 24 ± 0.8%, and an orbital inclination of i = 85.09 ± 0.45. We used the parallax from

Gaia EDR3 for calculating the absolute parameters of the binary system. This study suggested a new

linear ephemeris for BQ Ari, combining our new mid-eclipse times and the previous observations, which

we analyzed using the Monte Carlo Markov Chain (MCMC) method. We present the first analysis of the

system’s orbital period behavior by analyzing the O-C diagram using the Genetic Algorithm (GA) and the

MCMC approaches in OCFit code. We attempted to explain the analysis of the residuals of linear fit in the

O-C diagram with two approaches; “LiTE + Quadratic” and “Magnetic activity + Quadratic.” Although

we consider the magnetic activity to be probable, the system should be studied further in order to reveal the

nature of orbital period variations.

Keywords: Techniques: photometric; Stars: binaries: eclipsing; Stars: individual: BQ Ari.

DOI: 10.31857/S032001082106005X

¹Полная версия статьи публикуется только в английской версии журнала (Astronomy Letters v. 47, № 6, 2021).

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