scholarly journals Test of the Optimization Techniques for the Photometric Analysis of Contact Binaries

1992 ◽  
Vol 151 ◽  
pp. 387-390
Author(s):  
E. Lapasset ◽  
M. Gomez ◽  
R. Fariñas
Keyword(s):  
Optimization Techniques ◽  
Light Curves ◽  
Mass Ratio ◽  
Velocity Data ◽  
Photometric Analysis ◽  
Reliable Parameter ◽  
Contact Binaries ◽  
Cross Correlations ◽  
Grid Technique ◽  
Radial Velocity Data

We present light curve analyses of contact binaries and comparisons with previously published cross-correlations radial velocity data. The critical parameter q (mass-ratio) obtained from a grid technique is confronted with the spectroscopic value. For total eclipsing systems, both values are always in a good or reasonable agreement, including some stars with shallow light curves. For partial eclipsing systems, convergent photometric and spectroscopic results are obtained for an important set of stars. Two exceptions are V523 Cas and XY Boo for which some arguments are suggested. We concluded that reliable parameter determinations can be obtained from pure photometric solutions, by means of grid techniques.

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 UBVRI Photometric Analysis of the Solar-Type Eclipsing Binary TYC 3034-299-1

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Ronald G. Samec ◽  
Adam Jaso ◽  
Jesse White ◽  
Danny R. Faulkner ◽  
Nicholas Blum ◽  
...  
Keyword(s):  
Light Curve ◽  
Massive Star ◽  
Light Curves ◽  
Dark Spot ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Contact Binary ◽  
Solar Type ◽  
Curve Solution ◽  
Light Curve Solution

TYC 3034-0299-1 (CVn) is a magnetically active, contact binary, ROTSE variable. UBVRcIc light curves are presented along with a period study and a simultaneous UBVRI light curve solution. Our light curves show eclipse amplitudes of 0.72 and 0.62 mags (V) in the primary and secondary eclipses. Modeled results include a dark spot region, found at longitude 51°, a 24% Roche lobe fill-out, and a mass ratio of 0.48. A total eclipse is found to occur in the secondary eclipse making TYC 3034-0299-1 a W-type (less massive star is hotter) W UMa variable.

scholarly journals Precise Orbital Solutions for KEPLER Eclipsing Binaries of W UMa Type Showing Total Eclipses

2016 ◽  
Vol 33 ◽  
Author(s):  
H. V. Şenavcı ◽  
M. B. Doğruel ◽  
R. H. Nelson ◽  
M. Yılmaz ◽  
S. O. Selam
Keyword(s):  
High Precision ◽  
Binary Stars ◽  
Photometric Data ◽  
Eclipsing Binaries ◽  
Grid Search ◽  
Mass Ratio ◽  
Velocity Data ◽  
Flat Bottom ◽  
Mass Ratios ◽  
Radial Velocity Data

AbstractWe aim to discover the accuracy of photometric mass ratios (qph) determined for eclipsing binary stars, in the case of the system having at least one ‘flat bottom’ as a minimum profile, as well as the accuracy of data used in that sense. Within this context, we present the results of two-dimensional grid search (q – i) for some W UMa-type eclipsing binaries showing total eclipses, based on the high precision photometric data provided by the KEPLER Mission. The radial velocity data obtained for KIC10618253 in this study, enables us to compare both qph and the corresponding spectroscopic mass ratio (qsp) values. The results indicate that the high precision photometric data for overcontact eclipsing binaries showing total eclipses allow us to obtain the photometric mass ratios as accurate as the spectroscopic values.

scholarly journals Mass-Ratio Determination in Contact Binaries

1974 ◽  
Vol 59 ◽  
pp. 199-199
Author(s):  
J. B. Hutchings
Keyword(s):  
Spectroscopic Data ◽  
Theoretical Work ◽  
Light Curves ◽  
Line Profiles ◽  
Mass Ratio ◽  
Recent Theoretical Work ◽  
Mass Ratios ◽  
Contact Binaries ◽  
Ratio Determination ◽  
The Masses

In the wake of recent theoretical work on contact systems (e.g. Whelan, 1972; Biermann and Thomas, 1972; Lucy, 1968), it is of importance to determine fundamental data from observations. This has been done recently by several groups in analysing light curves (Mochnacki and Doughty, 1972; Hutchings and Hill, 1973; Wilson and Devinney, 1973), and it is found that shapes, temperature differences and distributions, and mass-ratios, can be determined in many cases. However, where spectroscopic data are also available, the mass-ratios are not always in agreement. Using the photometric models, it is possible (Hutchings, 1973) to calculate the distortion of line profiles resulting (primarily) from the non-uniform brightness over the component stars in these systems. This distortion leads to the characteristically observed ‘square’ velocity curves for the systems (e.g. Binnendijk, 1967). Correction for the effect in most cases (a) resolves the mass-ratio discrepancy and (b) leads to better estimates for the masses. The faintness of most contact systems makes detailed spectroscopy difficult, but there appears to be a need for further work in the directions outlined here to improve the fundamental data available on them. These results should also be borne in mind in inspecting previous work on contact binaries.

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 TraMoS

2020 ◽  
Vol 636 ◽  
pp. A98 ◽  
Author(s):  
Pía Cortés-Zuleta ◽  
Patricio Rojo ◽  
Songhu Wang ◽  
Tobias C. Hinse ◽  
Sergio Hoyer ◽  
...  
Keyword(s):  
Light Curves ◽  
Mean Square ◽  
Velocity Data ◽  
Orbital Parameters ◽  
Upper Limit ◽  
Dynamical Simulations ◽  
Extended Analysis ◽  
Periodic Trend ◽  
The Masses ◽  
Radial Velocity Data

We present 22 new transit observations of the exoplanets WASP-18Ab, WASP-19b, and WASP-77Ab, from the Transit Monitoring in the South project. We simultaneously model our newly collected transit light curves with archival photometry and radial velocity data to obtain refined physical and orbital parameters. We include TESS light curves of the three exoplanets to perform an extended analysis of the variations in their transit mid-time (TTV) and to refine their planetary orbital ephemeris. We did not find significant TTVRMS variations larger than 47, 65, and 86 s for WASP-18Ab, WASP-19b, and WASP-77Ab, respectively. Dynamical simulations were carried out to constrain the masses of a possible perturber. The observed mean square (RMS) could be produced by a perturber body with an upper limit mass of 9, 2.5, 11 and 4 M⊕ in 1:2, 1:3, 2:1, and 3:1 resonances in the WASP-18Ab system. In the case of WASP-19b, companions with masses up to 0.26, 0.65, 1, and 2.8 M⊕, in 1:2, 2:1, 3:1, and 5:3 resonances respectively, produce the RMS. For the WASP-77Ab system, this RMS could be produced by a planet with mass in the range of 1.5−9 M⊕ in 1:2, 1:3, 2:1, 2:3, 3:1, 3:5, or 5:3 resonances. Comparing our results with RV variations, we discard massive companions with 350 M⊕ in 17:5 resonance for WASP-18Ab, 95 M⊕ in 4:1 resonance for WASP-19b, and 105 M⊕ in 5:2 resonance for WASP-77Ab. Finally, using a Lomb-Scargle period search we find no evidence of a periodic trend on our TTV data for the three exoplanets.

scholarly journals Comprehensive photometric investigation of an active early K-type contact system—IL Cancri

2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Nian-Ping Liu ◽  
Thawicharat Sarotsakulchai ◽  
Somsawat Rattanasoon ◽  
Bin Zhang
Keyword(s):  
Primary Component ◽  
Light Curves ◽  
Mass Ratio ◽  
Highly Active ◽  
Type Contact ◽  
Contact Binaries ◽  
Contact Binary ◽  
Photometric Investigation ◽  
The Masses ◽  
Good Agreement

Abstract Comprehensive photometric investigation of the early K-type contact binary IL Cnc was carried out. A few light curves from both ground-based telescopes and the Kepler space telescope were obtained (or downloaded) and then analyzed in detail. They are mostly found to be asymmetric and there are even continuously changing O’Connell effects in the light curves from Kepler K2 data, suggesting the system to be highly active. Using the Wilson–Devinney code (version 2013), photometric solutions were derived and then compared. It is found that the calculation of the mass ratio is easily affected by the spot settings. Combining the radial velocities determined from LAMOST median resolution spectral data, the mass ratio of the binary components is found to be M2/M1 = 1.76 ± 0.05. The components are in shallow contact ($f\sim 9\%$) and have a temperature difference about T2 − T1 = −280 ± 20 K. The system is demonstrated to be W-subtype, which may be a common feature of K-type contact binaries. The masses of the binary components were estimated to be $M_1\sim 0.51\, M_{\odot }$ and $M_2\sim 0.90\, M_{\odot }$. The values are in good agreement with that deduced from the parallax data of Gaia. The results suggest that the primary component lacks luminosity compared with the zero main sequence. The Hα spectral line of the primary component is found to be peculiar. Combining newly determined minimum light times with those collected from literature, the orbital period of IL Cnc is studied. It is found that the (O − C) values of the primary minima show sinusoidal variation while those of the secondary do not. The oscillation is more likely to be caused by the starspot activities, yet this assumption needs more data to support.

scholarly journals Is there Na I in the atmosphere of HD 209458b?

2020 ◽  
Vol 635 ◽  
pp. A206 ◽  
Author(s):  
N. Casasayas-Barris ◽  
E. Pallé ◽  
F. Yan ◽  
G. Chen ◽  
R. Luque ◽  
...  
Keyword(s):  
High Resolution ◽  
Signal To Noise Ratio ◽  
Planetary Atmospheres ◽  
Light Curves ◽  
High Resolution Spectroscopy ◽  
Transmission Spectra ◽  
Spin Orbit ◽  
Velocity Data ◽  
Signal To Noise ◽  
Radial Velocity Data

HD 209458b was the first transiting planet discovered, and the first for which an atmosphere, in particular Na I, was detected. With time, it has become one of the most frequently studied planets, with a large diversity of atmospheric studies using low- and high-resolution spectroscopy. Here, we present transit spectroscopy observations of HD 209458b using the HARPS-N and CARMENES spectrographs. We fit the Rossiter-McLaughlin effect by combining radial velocity data from both instruments (nine transits in total), measuring a projected spin-orbit angle of − 1.6 ± 0.3 deg. We also present the analysis of high-resolution transmission spectroscopy around the Na I region at 590 nm, using a total of five transit observations. In contrast to previous studies where atmospheric Na I absorption is detected, we find that for all of the nights, whether individually or combined, the transmission spectra can be explained by the combination of the centre-to-limb variation and the Rossiter-McLaughlin effect. This is also observed in the time-evolution maps and transmission light curves, but at lower signal-to-noise ratio. Other strong lines such as Hα, Ca II IRT, the Mg I triplet region, and K I D1 are analysed, and are also consistent with the modelled effects, without considering any contribution from the exoplanet atmosphere. Thus, the transmission spectrum reveals no detectable Na I absorption in HD 209458b. We discuss how previous pioneering studies of this benchmark object may have overlooked these effects. While for some star–planet systems these effects are small, for other planetary atmospheres the results reported in the literature may require revision.

The first photometric analysis of two low mass ratio totally eclipsing contact binaries: TIC 393943031 and TIC 89428764

2021 ◽  
Author(s):  
Yanke Tang ◽  
Yani Guo ◽  
Kai Li ◽  
Ning Gai ◽  
Zhikai Li
Keyword(s):  
Mass Transfer ◽  
Primary Component ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Angular Momenta ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio ◽  
First Time

Abstract PhotometricanalysisofthecontactbinariesTIC393943031andTIC89428764was carried out usingTESS and SuperWASP data for the first time. Using Wilson-Devinneycode, we have discovered TIC 393943031 is a low-mass-ratio deep contact binary with a fillout factor of 50.9(±1)% and a mass ratio of q = 0.163 ± 0.001. TIC 89428764 is a medium and low-mass-ratio contact binary with a fillout factor of 34.5(±1)% and a mass ratio of q = 0.147±0.001. Furthermore, the period study reveals both the stars exhibit continuously increasing periods, the increasing rate is 4.21×10−7day ·year−1for TIC 393943031while 6.36 × 10−7day · year−1for TIC 89428764. The possible reason is mass transfer from the secondary component to the primary component for both the stars. Meanwhile, we discussed their evolutionary phases and orbital angular momenta.

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