scholarly journals Physical parameters of close binary systems: VIII

2021 ◽  
Author(s):  
K Gazeas ◽  
S Zola ◽  
A Liakos ◽  
B Zakrzewski ◽  
S M Rucinski ◽  
...  
Keyword(s):  
Binary Systems ◽  
Extreme Values ◽  
Close Binary ◽  
Physical Parameters ◽  
Evolutionary Status ◽  
Mass Ratio ◽  
Orbital Parameters ◽  
Contact Binaries ◽  
Contact Binary ◽  
Orbital Periods

Abstract This paper presents the results of a combined spectroscopic and photometric study of 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT Cnc, EE Cet, RW Com, KR Com, V401 Cyg, V345 Gem, AK Her, V502 Oph, V566 Oph, V2612 Oph, V1363 Ori, V351 Peg, V357 Peg, Y Sex, V1123 Tau and W UMa, which was conducted in the frame of the W UMa Project. Together with 51 already covered by the project and an additional 67 in the existing literature, these systems bring the total number of contact binaries with known combined spectroscopic and photometric solutions to 138. It was found that mass, radius and luminosity of the components follow certain relations along the MS and new empirical power relations are extracted. We found that 30 per cent of the systems in the current sample show extreme values in their parameters, expressed in their mass ratio or fill-out factor. This study shows that, among the contact binary systems studied, some have an extremely low mass ratio (q<0.1) or an ultra-short orbital period (Porb <0.25 d), which are expected to show evidence of mass transfer progress. The evolutionary status of these components is discussed with the aid of correlation diagrams and their physical and orbital parameters compared to those in the entire sample of known contact binaries. The existence of very short orbital periods confirms the very slow nature of the merging process, which seems to explain why their components still exist as MS stars in contact configurations even after several Gyr of evolution.

Distribution of physical parameters for 380 contact binaries in the Kepler field

2020 ◽  
Vol 72 (6) ◽  
Author(s):  
Xu-Zhi Li ◽  
Liang Liu ◽  
Li-Ying Zhu
Keyword(s):  
Binary Systems ◽  
Large Mass ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Eclipsing Binary ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio

Abstract We present the physical parameters (p, T, q, i, f) of 380 Kepler contact binary systems (hereafter called CBs). A statistical study on the CBs is carried out based on a Kepler photometric database. Our samples were selected from the Kepler Eclipsing Binary Catalogue of EW-type eclipsing binaries with periods around 0.2–1 d and amplitudes greater than $5\%$. The physical parameters were obtained by fitting the Kepler light curves with the Wilson–Devinney eclipsing binary modeling program. Our sample of CBs contains 160 A-type and 220 W-type CBs. The fill-out factor distribution indicated that CBs generally have shallow fill-out; the proportion of CBs with fill-out factors less than $30\%$ is around $70\%$, which may be related to the formation and evolution of the CBs. The period–temperature relationship of CBs is consistent with previous studies, which is the well-known period–color relationship. The distribution between mass ratio and fill-out factor can provide some information for studying the deep, low-mass ratio contact binaries and CBs which have a large mass ratio. The mass–radius diagram shows that there is a similar linear relationship between the primary and secondary stars while the primary stars are located almost on the ZAMS line; this could be related to the internal nuclear reaction within the primary and secondary stars.

Twin stars as tracers of binary evolution in the Kepler era

2021 ◽  
Author(s):  
Sara Bulut ◽  
Baris Hoyman ◽  
Ahmet Dervisoglu ◽  
Orkun Özdarcan ◽  
Ömür Cakilrli
Keyword(s):  
High Resolution ◽  
Internal Structure ◽  
Spectroscopic Analysis ◽  
Independent Method ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
Evolutionary Status ◽  
Mass Ratio ◽  
Orbital Parameters ◽  
Binary Evolution

Abstract We present results of the combined photometric and spectroscopic analysis of four systems, which are eclipsing binaries with a twin–component (mass ratio q ≃ 1). These are exceptional tools to provide information for probing the internal structure of stars. None of the systems were previously recognized as twin binaries. We used a number of high–resolution optical spectra to calculate the radial velocities and later combined them with photometry to derive orbital parameters. Temperatures and metallicities of systems were estimated from high-resolution spectra. For each binary, we obtained a full set of orbital and physical parameters, reaching precision below 3 per cent in masses and radii for whole pairs. By comparing our results with PARSEC and MIST isochrones, we assess the distance, age and evolutionary status of the researched objects. The primary and/or secondary stars of EPIC 216075815 and EPIC 202843107 are one of the cases where asteroseismic parameters of δ Sct and γ Dor pulsators were confirmed by an independent method and rare examples of the twin–eclipsing binaries, therefore the following analyses and results concern the pulsating nature of the components.

scholarly journals Searching for eclipsing binaries in the area of RA: 02h21m36s, Dec: +57○11′32″

2020 ◽  
Vol 497 (3) ◽  
pp. 3381-3392
Author(s):  
Di-Fu Guo ◽  
Kai Li ◽  
Xing Gao ◽  
Dong-Yang Gao ◽  
Zhi-Jian Xu ◽  
...  
Keyword(s):  
Binary Systems ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Mass Ratio ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio ◽  
Period Decrease ◽  
Cross Matching

ABSTRACT By analysing the data observed by the Comet Search Programme telescope at Xingming Observatory from 2018 October 11 to 2018 December 19, 24 eclipsing binaries were identified. By cross-matching with the VSX (AAVSO) website, we found that four binaries are newly discovered. By analysing the Transiting Exoplanet Survey Satellite (TESS) data, the light curves of 17 binaries were obtained. First photometric solutions of 23 binaries were obtained by simultaneously analysing all the light curves, except for NSVS 1908107 (first analysed by Pan et al.). Based on the photometric solutions, nine binaries belong to detached binary systems, ten binaries belong to semidetached binary systems, and five binaries belong to contact binary systems. Two W-subtype low-mass ratio contact binaries (the less massive components are hotter), with total eclipsing light curves, were identified: Mis V1395 is a deep contact binary (q = 0.150, $f=80{{\ \rm per\ cent}}$), while NSVS 1917038 is a low-mass ratio binary with an unexpectedly marginal contact degree (q = 1/6.839 = 0.146, $f=4{{\ \rm per\ cent}}$). The total eclipsing detached binary GSC 03698-00022 has an extremely low mass ratio of q = 0.085. The Algol-type binary NSVS 1908107 is also found to have an extremely low mass ratio of q = 0.081. The Algol-type binary DK Per exhibits a continuous period decrease at a rate of dP/dt = −1.26 × 10−7 d yr−1, which may result from the orbital angular momentum loss. Based on the light curves obtained from the TESS data, a pulsating binary candidate (NSVS 1913053) was found.

scholarly journals The EBLM Project

2019 ◽  
Vol 625 ◽  
pp. A150 ◽  
Author(s):  
Alexander von Boetticher ◽  
Amaury H. M. J. Triaud ◽  
Didier Queloz ◽  
Sam Gill ◽  
Pierre F. L. Maxted ◽  
...  
Keyword(s):  
Physical Properties ◽  
Stellar Evolution ◽  
Binary Systems ◽  
Close Binary ◽  
Low Mass Stars ◽  
Orbital Parameters ◽  
Eclipse Observations ◽  
Low Mass ◽  
Orbital Periods ◽  
Host Stars

Measurements of the physical properties of stars at the lower end of the main sequence are scarce. In this context we report masses, radii and surface gravities of ten very-low-mass stars in eclipsing binary systems, with orbital periods of the order of several days. The objects probe the stellar mass-radius relation in the fully convective regime, M⋆ ≲ 0.35 M⊙, down to the hydrogen burning mass-limit, MHB ∼ 0.07 M⊙. The stars were detected by the WASP survey for transiting extra-solar planets, as low-mass, eclipsing companions orbiting more massive, F- and G-type host stars. We use eclipse observations of the host stars, performed with the TRAPPIST, Leonhard Euler and SPECULOOS telescopes, and radial velocities of the host stars obtained with the CORALIE spectrograph, to determine the physical properties of the low-mass companions. Surface gravities of the low-mass companions are derived from the eclipse and orbital parameters of each system. Spectroscopic measurements of the host star effective temperature and metallicity are used to infer the host star mass and age from stellar evolution models for solar-type stars. Masses and radii of the low-mass companions are then derived from the eclipse and orbital parameters of the binary systems. The objects are compared to stellar evolution models for low-mass stars, to test for an effect of the stellar metallicity and orbital period on the radius of low-mass stars in close binary systems. Measurements are found to be in good agreement with stellar evolution models; a systematic inflation of the radius of low-mass stars with respect to model predictions is limited to 1.6 ± 1.2%, in the fully convective low-mass regime. The sample of ten objects indicates a scaling of the radius of low-mass stars with the host star metallicity. No correlation between stellar radii and the orbital periods of the binary systems is determined. A combined analysis with thirteen comparable objects from the literature is consistent with this result.

scholarly journals MULTICOLOR STUDY OF V1009 PER, A CLOSE BINARY SYSTEM AT THE BEGINNING OF THE OVERCONTACT PHASE, AND OF CRTS J031642.2+332639, A NEW BINARY SYSTEM IN THE SAME FIELD

2019 ◽  
Vol 55 (1) ◽  
pp. 65-72
Author(s):  
Raúl Michel ◽  
Francesco Acerbi ◽  
Carlo Barani ◽  
Massimiliano Martignoni
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Binary Systems ◽  
General Pattern ◽  
Close Binary System ◽  
Eclipsing Binaries ◽  
Close Binary ◽  
Mass Ratio ◽  
Period Variations ◽  
Contact Binaries

The first multicolor observations and light curve solutions of the eclipsing binary systems V1009 Per and CRTS J031642.2+332639 are presented. Using the 2005 version of the Wilson-Devinney code, both systems are found to be W UMa contact binaries. V1009 Per has a mass ratio of q = 0.362±0.002 and a shallow fill out parameter of f = 11.8 ± 0.6% while CRTS J031642.2+332639 has a mass ratio of q = 2.507±0.006 and a fill out of f = 13.6±0.4%. High orbital inclinations, i = 85◦.9 for V1009 Per and i = 83◦.2 for CRTS J031642.2+332639, imply that both systems are total eclipsing binaries and that the photometric parameters here obtained are reliable. Based on 16 times of minimum the orbital period variations of V1009 Per are discussed. The absolute dimensions of the systems are estimated and, from the log M − log L diagram, it is found that both components of the systems follow the general pattern of the W subtype W Ursae Majoris systems.

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.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

scholarly journals X-Ray Sources in Close Binary Systems

1974 ◽  
Vol 3 ◽  
pp. 89-107
Author(s):  
M. J. Rees
Keyword(s):  
Binary Systems ◽  
Close Binary ◽  
Rapid Variability ◽  
X Ray ◽  
Close Binary Systems ◽  
General Order ◽  
Typical Distances ◽  
Astronomical Research ◽  
Orbital Periods ◽  
Galactic Sources

The discovery by Giacconi and his colleagues of variable X-ray sources in close binary systems certainly ranks as one of the highlights of astronomical research during the last 3 years. These remarkable objects have already been extensively studied, by optical and radio observations as well as in the X-ray band; and they seem likely to prove as significant and far-reaching in their implications as pulsars.The ‘Third Uhuru Catalogue’ (Giacconi et al., 1973a) contains about 160 sources, of which about 100 lie in our Galaxy. Their distribution over the sky (together with other arguments) suggests that these sources have luminosities of the general order 1036–1038 erg s−1, and that their typical distances are ˜ 10kpc. These galactic sources generally display rapid variability. Little else is known about most of them, but they are probably of the same general class as systems such as Her X1, Cen X3, Cyg X1 and Cyg X3. These sources have been investigated in detail, and in all cases one infers a system where the X-ray source is orbiting around a relatively ordinary star. Six sources have been optically identified, and there are some others whose binary nature is established by the occurrence of an X-ray eclipse. Orbital periods range from 4.8 h (Cyg X3) up to ˜ 10 days.

scholarly journals Two Contact Binaries with Mass Ratios Close to the Minimum Mass Ratio

2021 ◽  
Vol 922 (2) ◽  
pp. 122
Author(s):  
Kai Li ◽  
Qi-Qi Xia ◽  
Chun-Hwey Kim ◽  
Shao-Ming Hu ◽  
Di-Fu Guo ◽  
...  
Keyword(s):  
Gyration Radius ◽  
Mass Ratio ◽  
Mass Ratios ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Ratio Limit ◽  
Low Mass Ratio ◽  
Diagram Analysis

Abstract The cutoff mass ratio is under debate for contact binaries. In this paper, we present the investigation of two contact binaries with mass ratios close to the low mass ratio limit. It is found that the mass ratios of VSX J082700.8+462850 (hereafter J082700) and 1SWASP J132829.37+555246.1 (hereafter J132829) are both less than 0.1 (q ∼ 0.055 for J082700 and q ∼ 0.089 for J132829). J082700 is a shallow contact binary with a contact degree of ∼19%, and J132829 is a deep contact system with a fill-out factor of ∼70%. The O − C diagram analysis indicated that the two systems manifested long-term period decreases. In addition, J082700 exhibits a cyclic modulation which is more likely resulting from the Applegate mechanism. In order to explore the properties of extremely low mass ratio contact binaries (ELMRCBs), we carried out a statistical analysis on contact binaries with mass ratios of q ≲ 0.1 and discovered that the values of J spin/J orb of three systems are greater than 1/3. Two possible explanations can interpret this phenomenon. One explanation is that some physical processes, unknown to date, are not considered when Hut presented the dynamic stability criterion. The other explanation is that the dimensionless gyration radius (k) should be smaller than the value we used (k 2 = 0.06). We also found that the formation of ELMRCBs possibly has two channels. The study of evolutionary states of ELMRCBs reveals that their evolutionary states are similar with those of normal W UMa contact binaries.

scholarly journals On the Distribution of Young Spectroscopic Binary Stars Over the Major Semiaxes of their Orbits

1982 ◽  
Vol 69 ◽  
pp. 129-131
Author(s):  
E.I. Popova ◽  
A.V. Tutukov ◽  
B.M. Shustov ◽  
L.R. Yungelson
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Physical Parameters ◽  
Origin And Evolution ◽  
Spectroscopic Binary ◽  
Visible Spectra ◽  
Major Semiaxes ◽  
The Masses

About 60% of stars of the disc population in our Galaxy are close binary systems (CBS). Half of the known CBS are spectroscopic binary stars (Kraitcheva et al., 1978).To know the distribution of a correlation between the masses of CBS components and semiaxes of their orbits is necessary for the investigation of the origin and evolution of CBS. For such statistical investigations, a catalogue of CBS was compiled at the Astronomical Council. The catalogue is based on the 6th Batten catalogue (Batten, 1967), its extensions (Pedoussant and Ginestet, 1971; Pedoussant and Carquillat, 1973) and data published up to the end of 1980 (Popova et al., 1981). Now it is recorded on magnetic tape and contains data on 1041 spectroscopic binaries; 333 of them are stars with two visible spectra. The latter are mostly systems prior to mass exchange and the distribution of physical parameters in these systems reflects the distribution and presumably conditions at the time of formation. Using some assumptions, we can obtain for spectroscopic binaries masses of the components M1 and M2 (or the ratio q = M1/M2) and semiaxes of their orbits. Masses of components with the known sin i were obtained by the usual technique; when sin i was not known, masses were estimated from the spectra. We shall discuss here the distribution of CBS in the M-a plane.

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