Orbital Period Changes and Global Evolution of Contact Binaries

2000 ◽  
pp. 649-657
Author(s):  
H. Rovithis-Livaniou ◽  
A. Kalimeris
Keyword(s):  
Orbital Period ◽  
Global Evolution ◽  
Contact Binaries

A high-mass-ratio red-dwarf contact binary with an extremely cool close-in red dwarf

2019 ◽  
Author(s):  
Xiao-Hui Fang ◽  
Shengbang Qian ◽  
Miloslav Zejda ◽  
Soonthornthum Boonrucksar ◽  
Xiao Zhou ◽  
...  
Keyword(s):  
Orbital Period ◽  
Light Curves ◽  
High Mass ◽  
Mass Ratio ◽  
Third Body ◽  
Dynamical Interaction ◽  
The Third ◽  
Short Period ◽  
Contact Binaries ◽  
Mass Component

Abstract 1SWASP J161335.80$-$284722.2 (hereafter J161335) is an eclipsing red-dwarf binary with an orbital period of $0.229778\:$d, which is around the short-period limit for contact binaries. Three sets of multi-color light curves of J161335 were obtained from different telescopes in 2015 and 2016 and are analyzed using the Wilson–Devinney method. We discovered that the system is a W-type contact system with a contact degree of 19% and a high mass ratio of 0.91. By using all available eclipse times, we found that the observed $-$ calculated $(O-C)$ diagram displays a cyclic oscillation with an amplitude of 0.00196($\pm 0.00006)\:$d and a period of 4.79($\pm 0.14)\:$yr while it undergoes a downward parabolic change. This downward variation corresponds to a continuous decrease in the orbital period at a rate of $dP/dt = -4.26(\pm$0.01) $\times$ 10$^{-7}\:$d$\:$yr$^{-1}$. The small-amplitude oscillation is explained as the light travel-time effect from the gravitational influence of a third body with a lowest mass of $M _{3}$ = 0.15($\pm 0.01)M_{\,\odot }$. In solving the light curves, we found that the third light is increasing, with the wavelength suggesting that the third body may be a cool red dwarf. This is in agreement with the results obtained by analyzing the $O-C$ diagram. The tertiary red dwarf is orbiting the central red-dwarf binary at an orbital separation of 2.8($\pm 0.2$) au. These results suggest that the J161335 system may be formed through early dynamical interaction where the original low-mass component was replaced by a higher-mass third body and the lower-mass component was kicked out to a wider orbit. In this way, a hierarchical triple system similar to J161335 with a high-mass-ratio binary and a small close-in third body is formed.

On orbital period changes of two low-mass-ratio and deep-contact binaries: FN Cam and KN Per

New Astronomy ◽  
2018 ◽  
Vol 62 ◽  
pp. 20-25 ◽  
Author(s):  
Ke Hu ◽  
Zhen-Hua Jiang ◽  
Yun-Xia Yu ◽  
Fu-Yuan Xiang
Keyword(s):  
Orbital Period ◽  
Mass Ratio ◽  
Contact Binaries ◽  
Low Mass ◽  
Low Mass Ratio

ORBITAL PERIOD CHANGES AND THEIR EVOLUTIONARY STATUS FOR WEAK-CONTACT BINARIES. II. CC COMAE BERENICES AND BV DRACONIS

2008 ◽  
Vol 137 (1) ◽  
pp. 236-245 ◽  
Author(s):  
Y.-G. Yang ◽  
G.-L. Lü ◽  
X.-G. Yin ◽  
C.-H. Zhu ◽  
K. Nakajima
Keyword(s):  
Orbital Period ◽  
Evolutionary Status ◽  
Contact Binaries ◽  
Weak Contact

Investigation of orbital period changes of selected contact binaries

2016 ◽  
Author(s):  
Muhammed Faruk Yıldırım ◽  
Faruk Soydugan
Keyword(s):  
Orbital Period ◽  
Contact Binaries

scholarly journals On the Spatial Density of W UMa Type Stars

1982 ◽  
Vol 69 ◽  
pp. 351-370
Author(s):  
E. Budding
Keyword(s):  
Spectral Type ◽  
Orbital Period ◽  
Binary Systems ◽  
Light Curves ◽  
Close Binary ◽  
Spatial Density ◽  
Type Orbital ◽  
Contact Binaries ◽  
Simplifying Assumptions ◽  
Binary Evolution

AbstractAttention is directed to the anomalous incidence of W UMa stars, which can be regarded as coming from not only a disproportionately large accumulation among close binary systems with primaries later than around mid-F spectral type, but also as a deficit at early types.Doubt is placed on the necessity of a straightforward identification of W UMa type light curves with contact binaries; and this allows some reduction in the estimated spatial incidence of contact binaries, from the figure of Van't Veer (1975), to 8 x 10-4 of all stars.The incidence is considered, with the aid of some simplifying assumptions, as an example of the general evolution of the distribution of binary systems in the primary spectral type - orbital period plane, subject to some known mechanisms of binary evolution.

scholarly journals The First Light Curve Modeling and Orbital Period Change Investigation of Nine Contact Binaries around the Short-period Cutoff

2020 ◽  
Vol 159 (5) ◽  
pp. 189
Author(s):  
Kai Li ◽  
Chun-Hwey Kim ◽  
Qi-Qi Xia ◽  
Raul Michel ◽  
Shao-Ming Hu ◽  
...  
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Period Change ◽  
Short Period ◽  
Contact Binaries ◽  
Curve Modeling

scholarly journals ORBITAL PERIOD CHANGES AND THEIR EVOLUTIONARY STATUS FOR THE WEAK-CONTACT BINARIES. III. AO CAMELOPARDALIS AND AH TAURI

2009 ◽  
Vol 139 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Y.-G. Yang ◽  
J.-Y. Wei ◽  
J. M. Kreiner ◽  
H.-L. Li
Keyword(s):  
Orbital Period ◽  
Evolutionary Status ◽  
Contact Binaries ◽  
Weak Contact

Orbital period cut-off of W UMa-type contact binaries

2020 ◽  
Vol 497 (3) ◽  
pp. 3493-3503 ◽  
Author(s):  
Xu-Dong Zhang ◽  
Sheng-Bang Qian
Keyword(s):  
Orbital Period ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Primary Star ◽  
The Past ◽  
Type Contact ◽  
Contact Binaries ◽  
Theoretical Mechanism ◽  
Orbital Periods ◽  
Comprehensive Study

ABSTRACT Period cut-off and period–colour relation are two special characters of W UMa-type contact binaries. In the past, many authors noted these two properties, however, a comprehensive study was still lacking. In order to reveal a theoretical mechanism behind these two peculiarities, we collected 365 contact binaries whose orbital periods, mass ratios, masses, and radii are compiled and attempted to make this idea come true by statistical means. Then, we obtained a lower limit (0.15 d) of orbital period by studying the correlation among four physical parameters (orbital period P, mass ratio q, mass of primary star M1, and separation between two components a). Furthermore, we used the most reliable parameters (P and q) to check our result, fortunately, all evidence indicated that our predicted value is credible. In the end, the reason why the period–colour relation exists was also discussed.

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