scholarly journals Light-time effect detected in fourteen eclipsing binaries

2020 ◽  
Vol 643 ◽  
pp. A130
Author(s):  
P. Zasche ◽  
R. Uhlař ◽  
P. Svoboda ◽  
P. Cagaš ◽  
M. Mašek
Keyword(s):  
Time Effect ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Physical Parameters ◽  
Third Body ◽  
Light Curve Analysis ◽  
Multiple Systems ◽  
The Third ◽  
Minimal Mass ◽  
Triple Star

The available minima timings of 14 selected eclipsing binaries (V1297 Cas, HD 24105, KU Aur, GU CMa, GH Mon, AZ Vel, DI Lyn, DK Her, GQ Dra, V624 Her, V1134 Her, KIC 6187893, V1928 Aql, V2486 Cyg) were collected and analyzed. Using the automatic telescopes, surveys, and satellite data, we derived more than 2500 times of eclipses, accompanied with our own ground-based observations. These data were used to detect the period variations in these multiple systems. The eclipse timing variations were described using the third-body hypothesis and the light-time effect. Their respective periods were derived as 2.5, 16.2, 27, 20, 64, 5.6, 22, 115, 27, 42, 6.9, 11.2, 4.1, and 8.4 years for these systems, respectively. The predicted minimal mass of the third body was calculated for each of the systems, and we discuss here their prospective detectability. The light curves of HD 24105, GH Mon, DK Her, V1134 Her, KIC 6187893, V1928 Aql, and V2486 Cyg were analyzed using the PHOEBE program, resulting in physical parameters of the components. Significant fractions of the third light were detected during the light-curve analysis, supporting our hypothesis of the triple-star nature of all these systems. The majority of these systems (nine out of 14) were already known as visual doubles. Our study shifts them to possible quadruples, what makes them even more interesting.

scholarly journals Possible substellar companions in low-mass eclipsing binaries: GU Bootis and YY Geminorum

2018 ◽  
Vol 620 ◽  
pp. A72
Author(s):  
M. Wolf ◽  
H. Kučáková ◽  
P. Zasche ◽  
J. Vraštil ◽  
K. Hoňková ◽  
...  
Keyword(s):  
Precise Determination ◽  
Time Effect ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
The Third ◽  
Low Mass ◽  
Orbital Periods ◽  
First Time

We present the next results of our long-term observational project to analyze the variations in the orbital periods of low-mass eclipsing binaries. About 70 new precise mid-eclipse times recorded with a CCD were obtained for two eclipsing binaries with short orbital periods: GU Boo (P = 0.​d49) and YY Gem (0.​d81). Observed-minus-calculated diagrams of the stars were analyzed using all reliable timings, and new parameters of the light-time effect were obtained. We derived for the first time or improved the short orbital periods of possible third bodies of 11 and 54 years for these low-mass binaries, respectively. We calculated that the minimum masses of the third components are close to 50 MJup, which corresponds to the mass of brown dwarfs. The multiplicity of these systems also plays an important role in the precise determination of their physical parameters.

Spectroscopic and photometric studies of four W UMa-type eclipsing binaries

2019 ◽  
Vol 487 (4) ◽  
pp. 5520-5534 ◽  
Author(s):  
Liu Long ◽  
Li-Yun Zhang ◽  
Xianming L Han ◽  
Hong-Peng Lu ◽  
Qing-feng Pi ◽  
...  
Keyword(s):  
Activity Cycle ◽  
Spectroscopic Studies ◽  
Magnetic Activity ◽  
Time Effect ◽  
Eclipsing Binaries ◽  
Third Body ◽  
Subtraction Technique ◽  
Orbital Parameters ◽  
The Third ◽  
First Time

Abstract We performed new photometric and spectroscopic studies on four W UMa-type eclipsing binaries (V400 Lyr, V574 Lyr, V1033 Her and V1062 Her). The main aims were to determine the orbital parameters and period variations of these four systems. We classified V574 Lyr, V1033 Her and V1062 Her spectral types based on LAMOST spectra, and used a spectra subtraction technique to measure the properties of the H α, H β and Ca ii H&K lines. We updated the ephemerides of these four systems, and conducted analyses of period variation for three systems (V574 Lyr, V1033 Her and V1062 Her). The period of V400 Lyr shows a continuous decrease, while that of V1033 Her continuously increases. Meanwhile, V574 Lyr and V1062 Her show a cyclic variation, caused by the light-time effect via the third body or magnetic activity cycle. The orbital and star-spot parameters of these four systems were obtained using the Wilson–Devinney program. This is the first time that precise orbital parameters have been obtained for V574 Lyr and V1062. We also concluded that these four objects are shallow contact eclipsing binaries with a cool spot on the primary. We found star-spot variabilities of about one month for V574 Lyr, and on long (years) time-scales for V1033 Her and V1062 Her. There are also obvious variations in the differences of light-curve maxima between 0.25 and 0.75 phases.

V1005 Her: a solar-type shallow-contact binary in a triply fossil system

2019 ◽  
Vol 489 (2) ◽  
pp. 2677-2684 ◽  
Author(s):  
L-Y Zhu ◽  
Z H Wang ◽  
X M Tian ◽  
L J Li ◽  
X Gao
Keyword(s):  
Magnetic Activity ◽  
Light Curves ◽  
Cyclic Variation ◽  
Third Body ◽  
Light Curve Analysis ◽  
Short Period ◽  
Contact Binary ◽  
Solar Type ◽  
Activity Cycles ◽  
Minimal Mass

ABSTRACTFour sets of complete multicolour light curves of the short-period solar-type eclipsing binary V1005 Her are presented. It is found that the depth of the primary minima in the light curves went deeper from 2013 to 2018, and then became shallower again in 2019, while those of the secondary minima were unchanged. The total-eclipse characteristics in the light curves enable us to determine reliable photometric solutions of this system. Our results from the detailed light-curve analysis show that V1005 Her is a W-type shallow-contact binary with spot activities. We have monitored this system for 7 yr and 22 new times of light minimum have been determined. Together with those collected from the literature, we investigate its Observed-Calculated O–C curve and detect a cyclic variation. Because of the insufficient energy, this cyclic change cannot be explained by magnetic activity cycles of the components even if it has high spots activities. The detected cyclic variation is more plausible as the results of the light-time effect due to the existence of a third body orbiting around the central binary. The minimal mass of the additional stellar companion is determined around 0.45 M⊙ in both circular orbit and eccentric orbit cases when a total mass of 1.2 M⊙ for the binary is adopted. This mass is larger than that of the less massive component of the central binary. It implies that the secondary body was not replaced by the third body during early stellar interactions, suggesting that it is a fossil system and keeps original dynamical information.

scholarly journals New inclination changing eclipsing binaries in the Magellanic Clouds

2018 ◽  
Vol 609 ◽  
pp. A46 ◽  
Author(s):  
J. Juryšek ◽  
P. Zasche ◽  
M. Wolf ◽  
J. Vraštil ◽  
D. Vokrouhlický ◽  
...  
Keyword(s):  
Milky Way ◽  
Orbital Plane ◽  
Magellanic Clouds ◽  
Eclipsing Binaries ◽  
Formation Mechanisms ◽  
Physical Parameters ◽  
Milky Way Galaxy ◽  
Orbital Inclination ◽  
Multiple Systems ◽  
The Third

Context. Multiple stellar systems are unique laboratories for astrophysics. Analysis of their orbital dynamics, if well characterized from their observations, may reveal invaluable information about the physical properties of the participating stars. Unfortunately, there are only a few known and well described multiple systems, this is even more so for systems located outside the Milky Way galaxy. A particularly interesting situation occurs when the inner binary in a compact triple system is eclipsing. This is because the stellar interaction, typically resulting in precession of orbital planes, may be observable as a variation of depth of the eclipses on a long timescale. Aims. We aim to present a novel method to determine compact triples using publicly available photometric data from large surveys. Here we apply it to eclipsing binaries (EBs) in Magellanic Clouds from OGLE III database. Our tool consists of identifying the cases where the orbital plane of EB evolves in accord with expectations from the interaction with a third star. Methods. We analyzed light curves (LCs) of 26121 LMC and 6138 SMC EBs with the goal to identify those for which the orbital inclination varies in time. Archival LCs of the selected systems, when complemented by our own observations with Danish 1.54-m telescope, were thoroughly analyzed using the PHOEBE program. This provided physical parameters of components of each system. Time dependence of the EB’s inclination was described using the theory of orbital-plane precession. By observing the parameter-dependence of the precession rate, we were able to constrain the third companion mass and its orbital period around EB. Results. We identified 58 candidates of new compact triples in Magellanic Clouds. This is the largest published sample of such systems so far. Eight of them were analyzed thoroughly and physical parameters of inner binary were determined together with an estimation of basic characteristics of the third star. Prior to our work, only one such system was well characterized outside the Milky Way galaxy. Therefore, we increased this sample in a significant way. These data may provide important clues about stellar formation mechanisms for objects with different metalicity than found in our galactic neighborhood.

scholarly journals TIC 278825952: a triply eclipsing hierarchical triple system with the most intrinsically circular outer orbit

2020 ◽  
Vol 498 (4) ◽  
pp. 6034-6043
Author(s):  
T Mitnyan ◽  
T Borkovits ◽  
S A Rappaport ◽  
A Pál ◽  
P F L Maxted
Keyword(s):  
Massive Star ◽  
Spectral Energy Distribution ◽  
Time Effect ◽  
Photometric Data ◽  
Spectral Energy ◽  
Star System ◽  
Third Body ◽  
The Third ◽  
Mutual Inclination ◽  
Triple Star

ABSTRACT We report the discovery of a compact triply eclipsing triple star system in the southern continuous viewing zone of the TESS space telescope. TIC 278825952 is a previously known, but unstudied circular eclipsing binary with a period of 4.781 d with a tertiary component in a wider, circular orbit of 235.55-d period that was found from three sets of third-body eclipses and from light travel-time effect dominated eclipse timing variations. We performed a joint photodynamical analysis of the eclipse timing variation curves, photometric data, and the spectral energy distribution, coupled with the use of PARSEC stellar isochrones. We find that the inner binary consists of slightly evolved, near twin stars of masses of 1.12 and 1.09 M⊙ and radii of 1.40 and 1.31 R⊙. The third, less massive star has a mass of 0.75 M⊙ and radius of 0.70 R⊙. The low mutual inclination and eccentricities of the orbits show that the system is highly coplanar and surprisingly circular.

scholarly journals New Data on the Eclipsing Binary V1848 Ori and Improved Orbital and Light Curve Solutions

2020 ◽  
Vol 29 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Fatemeh Davoudi ◽  
Atila Poro ◽  
Fahri Alicavus ◽  
Afshin Halavati ◽  
Saeed Doostmohammadi ◽  
...  
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Mass Function ◽  
Light Curves ◽  
Complete Analysis ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Third Body ◽  
Eclipsing Binary

AbstractNew observations of the eclipsing binary system V1848 Ori were carried out using the V filter resulting in a determination of new times of minima and new ephemeris were obtained. We presented the first complete analysis of the system’s orbital period behavior and analysis of O-C diagram done by the GA and MCMC approaches in OCFit code. The O-C diagram demonstrates a sinusoidal trend in the data; this trend suggests a cyclic change caused by the LITE effect with a period of 10.57 years and an amplitude of 7.182 minutes. It appears that there is a third body with mass function of f (m3) = 0.0058 M⊙ in this binary system. The light curves were analyzed using the Wilson-Devinney code to determine some geometrical and physical parameters of the system. These results show that V1848 Ori is a contact W UMa binary system with the mass ratio of q = 0.76 and a weak fillout factor of 5.8%. The O’Connell effect was not seen in the light curve and there is no need to add spot.

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.

scholarly journals The Third Body in the Eclipsing Binary AV CMi: Hot Jupiter or Brown Dwarf?

2011 ◽  
Vol 7 (S282) ◽  
pp. 57-58
Author(s):  
Alexios Liakos ◽  
Dimitris Mislis ◽  
Panagiotis Niarchos
Keyword(s):  
Light Curves ◽  
Third Body ◽  
Brown Dwarf ◽  
Eclipsing Binary ◽  
The Third ◽  
Hot Jupiter

AbstractNew transit light curves of the third body in the system AV CMi have been obtained. The eclipsing pair's light curves were re-analysed with the W-D code and new absolute elements were derived for the two components. Moreover the new light curves (together with those given by Liakos & Niarchos 2010) of the third body transiting one of the components were analysed with the Photometric Software for Transits (PhoS-T). The results from both analyses are combined with the aim to study the nature of the third component.

scholarly journals High-Level Magnetic Activity on a Low-Mass Close Binary: GSC 02038-0293

2012 ◽  
Vol 29 (2) ◽  
pp. 150-160 ◽  
Author(s):  
H. A. Dal ◽  
E. Sipahi ◽  
O. Özdarcan
Keyword(s):  
Light Curve ◽  
Active Component ◽  
Magnetic Activity ◽  
Curve Analysis ◽  
Light Curves ◽  
Close Binary ◽  
Physical Parameters ◽  
Light Curve Analysis ◽  
Low Mass ◽  
High Level

AbstractTaking into account results obtained from light-curve analysis and out-of-eclipse analyses, we discuss the nature of GSC 02038-00293 and also its magnetic activity behaviour.We obtained light curves of the system during observing seasons 2007, 2008 and 2011. We obtained its secondary minimum clearly in I-band observations in 2008 for the first time. Analysing this light curve, we found the physical parameters of the components. The light-curve analysis indicates that the possible mass ratio of the system is 0.35. We obtained the remaining V-band light curves, extracting the eclipses. We modelled these remaining curves using the SPOTMODEL program and found possible spot configurations of the magnetically active component for each observing season. The models demonstrated that there are two active longitudes for the active component. The models reveal that both active longitudes migrate in the direction of decreasing longitude. We also examined the light curves in out-of-eclipse phases with respect to minimum and maximum brightness, amplitude, etc. The amplitude of the curves during out-of-eclipse phases varies in a sinusoidal way with a period of ∼8.9 yr; the mean brightness of the system is dramatically decreasing. The phases of the deeper minimum during out-of-eclipse periods exhibit a migration toward decreasing phase.

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