arXiv subjects

Sabrina Baudart

Publications and source records attributed to Sabrina Baudart.

6 recordsLinked to original sources

arXiv2026

BSN-VIII: Detailed Photometric Modeling of Ten W UMa Contact Binaries and a Revised Empirical Period-Mass Relationship

This study continues our ongoing research on contact binary systems by presenting a detailed analysis of 10 targets. Ground-based observations from six different observatories were conducted and used together with TESS data for the analysis process. Photometric data from our observations were reduced with the recently developed AutoWISP pipeline, yielding high-quality light curves with reliable precision for analysis. An investigation of orbital period variations identifies long-term trends in six of the ten analyzed binaries, including three that also display cyclic variations. Four targets show essentially constant orbital periods. The secular trends are attributed to mass transfer. The cyclic modulations in three systems are caused by either magnetic activity cycles or the Light-Travel Time Effect (LTTE) of a third body, while that in the remaining system is solely due to the LTTE. The BSN application was used to model the photometric light curves of the 10 target binaries. Iterative fitting and MCMC refinement provided robust estimates of the system parameters, while starspot modeling was applied for systems showing O'Connell-effect asymmetries. We refine the empirical orbital period-mass relationship for short-period contact binaries by analyzing a homogeneous dataset of systems and deriving an updated primary-mass calibration based on the spectroscopic subset. Using this calibrated relation, the fundamental parameters of the studied systems were subsequently estimated.

astro-ph.SR↗

arXiv2026

BSN: Light Curve Modeling and Orbital Period Analysis of the Contact Binaries OV Leo and V339 Leo

We present a combined photometric and orbital period analysis of the contact binary systems OV Leo and V339 Leo using ground-based observations together with TESS photometry. The light curves were modeled with the BSN software through a Markov Chain Monte Carlo approach, providing physical estimates of the system parameters and their uncertainties. OV Leo is analyzed photometrically for the first time, while V339 Leo is reexamined using new observations and an updated modeling methodology. The light curve analysis show that both targets are W-subtype contact binaries in shallow-contact configurations. The O'Connell effect detected in V339 Leo is reproduced with a cool starspot model, whereas no spot is required for OV Leo. Three-dimensional geometric models further indicate that OV Leo undergoes total eclipses, while V339 Leo exhibits partial eclipses. Orbital period analysis based on eclipse timing extractions reveals opposite long-term period variations in the two systems, suggesting ongoing mass transfer under the assumption of conservative mass transfer. The absolute parameters were derived using the Gaia parallaxes, the photometric light curve solution, and standard astrophysical equations.

astro-ph.SR↗

arXiv2024

BSN: The First Photometric Analysis of Contact Binary Systems V1961 Cyg and V0890 Lyr

We presented the first photometric analysis of the V1961 Cyg and V0890 Lyr binary systems. We observed and analyzed these systems at an observatory in France as part of the Binary Systems of South and North (BSN) Project. We extracted and collected the times of minima from the observations and literature and presented a new ephemeris for each system. Due to the few observations about these systems over the years, both O-C diagrams were fitted linearly. The PHysics Of Eclipsing BinariEs (PHOEBE) Python code and the Markov Chain Monte Carlo (MCMC) method were used to light curve solutions. The light curve solution required a cold starspot on the hotter component in the V1961 Cyg binary system. We compared and have close agreements between our mass ratios' results from the light curve analysis processes and a new method based on the light curve derivative. We estimated the absolute parameters using an empirical relationship between the semi-major axis and orbital period for contact binary systems. The results show V1961 Cyg and V0890 Lyr are W-type contact binary systems. We displayed stars and systems' positions in the M-L, M-R, and logM_{tot}-logJ_0 diagrams. We also presented a new relationship between mass ratio and luminosity ratio.

astro-ph.SR↗

arXiv2024

First Light Curve Analysis of NSVS 8294044, V1023 Her, and V1397 Her Contact Binary Systems

The first photometric light curve investigation of the NSVS 8294044, V1023 Her, and V1397 Her binary systems is presented. We used ground-based observations for the NSVS 8294044 system and Transiting Exoplanet Survey Satellite (TESS) data for V1023 Her and V1397 Her. The primary and secondary times of minima were extracted from all the data, and by collecting the literature, a new ephemeris was computed for each system. Linear fits for the O-C diagrams were conducted using the Markov chain Monte Carlo (MCMC) method. Light curve solutions were performed using the PHysics Of Eclipsing BinariEs (PHOEBE) Python code and the MCMC approach. The systems were found to be contact binary stars based on the fillout factor and mass ratio. V1023 Her showed the O'Connell effect, and a cold starspot on the secondary component was required for the light curve solution. The absolute parameters of the system were estimated based on an empirical relationship between orbital period and mass. We presented a new T-M equation based on a sample of 428 contact binary systems and found that our three target systems were in good agreement with the fit. The positions of the systems were also depicted on the M-L, M-R, q-L_{ratio}, and M_{tot}-J_0 diagrams in the logarithmic scales.

astro-ph.SR↗

arXiv2024

BSN: Photometric Light Curve Analysis of Two Contact Binary Systems LS Del and V997 Cyg

The light curve analyses and orbital period variations for two contact binary stars, LS Del and V997 Cyg, were presented in this work which was conducted in the frame of the Binary Systems of South and North (BSN) Project. Ground-based photometric observations were performed at two observatories in France. We used the TESS (Transiting Exoplanet Survey Satellite) data for extracting times of minima and light curve analysis of the target systems. The O-C diagram for both systems displays a parabolic trend. LS Del and V997 Cyg's orbital periods are increasing at a rate of dP/dt= 7.20*10^{-08} d yr^{-1} and dP/dt= 2.54*10^{-08} d yr^{-1}, respectively. Therefore, it can be concluded that the mass is being transferred from the less massive star to the more massive component with a rate of dM/dt= -1.96*10^{-7} M_Sun yr^{-1} for the LS Del system, and dM/dt= -3.83*10^{-7} M_Sun yr^{-1} for V997 Cyg. The parameters of the third possible object in the system were also considered. The PHysics Of Eclipsing BinariEs (PHOEBE) Python code was used to analyze the light curves. The light curve solutions needed a cold starspot due to the asymmetry in the LS Del system's light curve maxima. The mass ratio, fill-out factor, and star temperature all indicate that both systems are contact binary types in this investigation. Two methods were used to estimate the absolute parameters of the systems: one method used the parallax of Gaia DR3, and the other used a P-M relationship. The positions of the systems were also depicted on the M-L, M-R, q-L_{ratio}, and logM_{tot}-logJ_0 diagrams. We recommended that further observations and investigations be done on the existence of the fourth body in this system.

astro-ph.SR↗

arXiv2023

The First Photometric Study of the Binary System CSS J003106.8+313347

We performed the first photometric study of the CSS J003106.8+313347 W Ursae Majoris (W UMa)-type system based on ground-based observations. We extracted times of minima from our observations and proposed a linear ephemeris based on the increasing incline of the orbital period using a Markov chain Monte Carlo (MCMC) approach. The PHOEBE Python code and the MCMC approach were used for the light curve analysis. This system did not need starspots for the light curve analysis. Mass ratio, fillout factor, and inclination were obtained as 0.699, 0.322, and 60.6deg respectively. We also estimated the absolute parameters of the system using the Gaia DR3 parallax method. Therefore, the masses, radii, and luminosities have been determined to be M1=1.675, M2=1.171, R1=1.292, R2=1.097, L1=1.348, and L2=1.221. The orbital angular momentum (J0) of the CSS J003106.8+313347 illustrates that this system is located in a region of contact binaries. The positions of the primary and secondary components on the Hertzsprung-Russell (HR) diagram are depicted.

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