No Arabic abstract
The photometric and spectroscopic data for three double-lined detached eclipsing binaries were collected from the photometric and spectral surveys. The light and radial velocity curves of each binary system were simultaneously analyzed by using Wilson-Devinney (WD) code, and the absolute physical and orbital parameters of these binaries were derived. The masses of both components of ASASSN-V J063123.82+192341.9 were found to be $M_1 = 1.088 pm 0.016$ and $M_2 = 0.883 pm 0.016 M_{odot}$; and those of ASAS J011416+0426.4 were determined to be $M_1 = 0.934 pm 0.046$ and $M_2 = 0.754 pm 0.043 M_{odot}$; those of MW Aur were derived to be $M_1 = 2.052 pm 0.196$ and $M_2 = 1.939 pm 0.193 M_{odot}$. At last, the evolutionary status of these detached binaries was discussed based on their absolute parameters and the theoretical stellar models. Keywords: Stars: binaries: eclipsing $-$ stars: fundamental parameters$-$ stars: evolution $-$ stars: individual: ASASSN-V J063123.82+192341.9, ASAS J011416+0426.4 and MW Aur
Detached eclipsing binaries are remarkable systems to provide accurate fundamental stellar parameters. The fundamental stellar parameters and the metallicity values of stellar systems are needed to deeply understand the stellar evolution and formation. In this study, we focus on the detailed spectroscopic and photometric studies of three detached eclipsing binary systems, V372,And, V2080,Cyg, and CF,Lyn to obtain their accurate stellar, atmospheric parameters,and chemical compositions. An analysis of light and radial velocity curves was carried out to derive the orbital and stellar parameters. The disentangled spectra of component stars were obtained for the spectroscopic analysis. Final teff, logg, $xi$, vsini, parameters and the element abundances of component stars were derived by using the spectrum synthesis method. The fundamental stellar parameters were determined with a high certainty for V372,And, V2080,Cyg ($sim$$1-2$%) and with an accuracy for CF,Lyn ($sim$$2-6$%). The evolutionary status of the systems was examined and their ages were obtained. It was found that the component stars of V2080,Cyg have similar iron abundance which is slightly lower than solar iron abundance. Additionally, we showed that the primary component of CF,Lyn exhibits a non-spherical shape with its 80% Roche lobe filling factor. It could be estimated that CF,Lyn will start its first Roche overflow in the next 0.02,Gyr.
We report an analysis of two poorly studied systems GSC 04396-00605 and GSC 04395-00485, which were recently named as V0455 Dra and V0454 Dra, respectively. For two eclipsing stars, the periods and epochs were significantly corrected using our extensive data. The phenomenological characteristics of the mean light curves were determined using the New Algol Variable (NAV) algorithm. The individual times of Maxima/Minima (ToM) were determined using the newly developed software MAVKA, which outputs the accurate parameters using the asymptotic parabola approximations. The light curves were approximated using the Wilson-Devinney model, the best fit parameters are listed. For both systems, the presence of the dark spot is justified, the parameters are estimated. Both systems classified to be overcontact binaries of EW type. The observations were obtained using the 1-m Korean telescope of the LOAO while monitoring the cataclysmic variable DO Dra within the Inter-Longitude Astronomy (ILA) project.
V923 Sco is a bright ($V$ = 5.91), nearby ($pi$ = 15.46$pm$0.40 mas) southern eclipsing binary. Because both components are slow rotators, the minimum masses of the components are known with 0.2% precision from spectroscopy. The system seems ideal for very precise mass, radius, and luminosity determinations and, owing to its proximity and long orbital period ($sim$ 34.8 days), promises to be resolved with long-baseline interferometry. The principal aim is very accurate determinations of absolute stellar parameters for both components of the eclipsing binary and a model-independent determination of the distance.} New high-precision photometry of both eclipses of V923 Sco with the MOST satellite was obtained. The system was spatially resolved with the VLTI AMBER, PIONIER, and GRAVITY instruments at nine epochs. Combining the projected size of the spectroscopic orbit (in km) and visual orbit (in mas) the distance to the system is derived. Simultaneous analysis of photometric, spectroscopic, and interferometric data was performed to obtain a robust determination of the absolute parameters. Very precise absolute parameters of the components were derived in spite of the parameter correlations. The primary component is found to be overluminous for its mass. Combining spectroscopic and interferometric observations enabled us to determine the distance to V923 Sco with better than 0.2% precision, which provides a stringent test of Gaia parallaxes. It is shown that combining spectroscopic and interferometric observations of nearby eclipsing binaries can lead to extremely accurate parallaxes and stellar parameters.
High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033 Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that Gaia distance can be applied to estimate absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated by using their Gaia distances. The evolutionary status of contact binaries was studied, we found that the A- and W- subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It is discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.
We present the results of a spectroscopic campaign on eclipsing binaries with long orbital period (P = 20 - 75 d) carried out with the CHIRON spectrograph. Physical and orbital solutions for seven systems were derived from the V-band, and I-band ASAS, WASP, and TESS photometry, while radial velocities were calculated from high quality optical spectra using a two-dimensional cross-correlation technique. The atmospheric parameters of the stars have been determined from the separated spectra. Most of our targets are composed of evolved stars (sub-giants or red giants) but two systems show components in different phases of evolution and one possible merger. For four binaries the masses and radii of the components were obtained with precision better than 3%. These objects provide very valuable information on stellar evolution.