- ID:
- ivo://CDS.VizieR/J/AN/325/424
- Title:
- SV Cam VB differential photometry
- Short Name:
- J/AN/325/424
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present analysis and spot solutions based on yet unpublished B and V photoelectric observations on the active binary system SV Cam, carried out at Piszkesteto Mountain Station of Konkoly Observatory Budapest. The present spot solutions are based on the observed light curves in September 1993 and July 1994. Comparison of recent and older spot solutions - taken from the literature - suggests long term differences, but these divergences might be caused by some differences of the applied computational methods.
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- ID:
- ivo://CDS.VizieR/J/AJ/143/34
- Title:
- SZ Her BVRI light curves
- Short Name:
- J/AJ/143/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiband CCD photometric observations of SZ Her were obtained between 2008 February and May. The light curve was completely covered and indicated a significant temperature difference between both components. The light-curve synthesis presented in this paper indicates that the eclipsing binary is a classical Algol-type system with parameters of q=0.472, i=87.57{deg}, and {Delta}(T_1_-T_2_)=2381K; the primary component fills approximately 77% of its limiting lobe and is slightly larger than the lobe-filling secondary component. More than 1100 times of minimum light spanning more than a century were used to study an orbital behavior of the binary system. It was found that the orbital period of SZ Her varied due to a combination of two periodic variations with cycle lengths of P_3_=85.8yr and P_4_=42.5yr and semi-amplitudes of K_3_=0.013days and K_4_=0.007days, respectively. The most reasonable explanation for these variations is a pair of light-time effects driven by the possible existence of two M-type companions with minimum masses of M_3_=0.22M_{sun}_ and M_4_=0.19M_{sun}_ that are located close to the 2:1 mean motion resonance. If two additional bodies exist, then the overall dynamics of the multiple system may provide a significant clue to the formation and evolution of the eclipsing pair.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/3473
- Title:
- Temperatures of Kepler eclipsing binaries
- Short Name:
- J/MNRAS/437/3473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have combined the Kepler Eclipsing Binary Catalogue with information from the HES (Everett et al., 2012PASP..124..316E), KIS (Greiss et al, 2012AJ....144...24G, Cat. J/AJ/144/24) and 2MASS (Cat. II/246) photometric surveys to produce spectral energy distribution fits to over 2600 eclipsing binaries in the catalogue over a wavelength range of 0.36-2.16{AA}. We present primary (T1) and secondary (T2) stellar temperatures, plus information on the stellar radii and system distance ratios. The derived temperatures are on average accurate to 370K in T1 and 620K in T2. Our results improve on the similarly derived physical parameters of the Kepler Input Catalogue through consideration of both stars of the binary system rather than a single star model, and inclusion of additional U-band photometry. We expect these results to aid future uses of the Kepler eclipsing binary data, both in target selection and to inform users of the extremely high-precision light curves available. We do not include surface gravities or system metallicities, as these were found to have an insignificant effect on the observed photometric bands.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A17
- Title:
- TESS eclipsing binaries apsidal motion
- Short Name:
- J/A+A/654/A17
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The measurement of apsidal motion rates in eccentric eclipsing binaries is a unique way to gain insight into the internal structure of stars through the internal density concentration parameter,k2. High-quality physical parameters of the stellar components,together with precise measurements of the advance of the periastron, are needed for the comparison with values derived from models. As a product of the TESS mission, high-precision light curves of a large number of eclipsing binaries are now available. Using a selection of well-studied, double-lined eccentric eclipsing binary systems, we aim to determine their apsidal motion rates and place constraints on the internal density concentration and compare with the predictions from state-of-the-art theoretical models. We compute times of minimum light using the TESS light curves of 34 eclipsing binaries with precise absolute parameters. We use the changing difference over time between primary and secondary eclipse timings to determine the apsidal motion rate. To extend the time baseline, we combine the high-precision TESS timings with reliable archival data. On the other hand, for each component of our sample of double-lined eclipsing binaries we computed grids of evolutionary stellar models for the observed stellar mass exploring ranges of values of the overshooting parameter, fov, the mixing-length parameter and the metallicity. To find the best solution for the two components we adopt a chi-squared statistic to infer the optimal values of the overshooting parameter and the mixing-length parameter. The theoretical internal structure constants to be compared with the observed values were calculated by integrating the differential equations of Radau for each stellar model. We have determined the apsidal motion rate of 27 double-lined eclipsing binaries with precise physical parameters. The obtained values, corrected for their relativistic contribution, yield precise empirical parameters of the internal stellar density concentration. The comparison of these results with the predictions based on new theoretical models shows very good agreement. Small deviations are identified but remain within the observational uncertainties and the path for a refined comparison is indicated.
- ID:
- ivo://CDS.VizieR/J/A+A/652/A120
- Title:
- TESS OBA-type eclipsing binaries
- Short Name:
- J/A+A/652/A120
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Intermediate- to high-mass stars are the least numerous types of stars and they are less well understood than their more numerous low-mass counterparts in terms of their internal physical processes. Modelling the photometric variability of a large sample of main-sequence intermediate- to high-mass stars in eclipsing binary systems will help to improve the models for such stars. Our goal is to compose a homogeneously compiled sample of main-sequence intermediate- to high-mass OBA-type dwarfs in eclipsing binary systems from TESS photometry. We search for binaries with and without pulsations and determine their approximate ephemerides. Our selection starts from a catalogue of dwarfs with colours corresponding to those of OBA-type dwarfs in the TESS Input Catalog. We develop a new automated method aimed at detecting eclipsing binaries in the presence of strong pulsational and/or rotational signal relative to the eclipse depths and apply it to publicly available 30-min cadence TESS light curves. Using targets with TESS magnitudes below 15 and cuts in the 2MASS magnitude bands of J-H<0.045 and J-K<0.06 as most stringent criteria, we arrive at a total of 189 981 intermediate- to high-mass candidates, 91193 of which have light curves from at least one of two data reduction pipelines. The eclipsing binary detection and subsequent manual check for false positives resulted in 3155 unique OBA-type eclipsing binary candidates. Our sample of eclipsing binary stars in the intermediate- to high-mass regime allows for future binary (and asteroseismic) modelling with the aim to better understand the internal physical processes in this hot part of the main sequence.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A64
- Title:
- TESS time of eclipse of 15 eclipsing binaries
- Short Name:
- J/A+A/649/A64
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The change in the argument of periastron of eclipsing binaries, that is, the apsidal motion caused by classical and relativistic effects, can be measured from variations in the difference between the time of minimum light of the primary and secondary eclipses. Poor apsidal motion rate determinations and large uncertainties in the classical term have hampered previous attempts to determine the general relativistic term with sufficient precision to test general relativity predictions. As a product of the TESS mission, thousands of high-precision light curves from eclipsing binaries are now available. Using a selection of suitable well-studied eccentric eclipsing binary systems, we aim to determine their apsidal motion rates and place constraints on key gravitational parameters. We compute the time of minimum light from the TESS light curves of 15 eclipsing binaries with precise absolute parameters and with an expected general relativistic contribution to the total apsidal motion rate of greater than 60%. We use the changing primary and secondary eclipse timing differences over time to compute the apsidal motion rate, when possible, or the difference between the linear periods as computed from primary and secondary eclipses. For a greater time baseline we carefully combine the high-precision TESS timings with archival reliable timings. We determine the apsidal motion rate of 9 eclipsing binaries, 5 of which are reported for the first time. From these, we are able to measure the general relativistic apsidal motion rate of 6 systems with sufficient precision to test general relativity for the first time using this method. This test explores a regime of gravitational forces and potentials that had not been probed before. We find perfect agreement with theoretical predictions, and we are able to set stringent constraints on two parameters of the parametrised post-Newtonian formalism.
- ID:
- ivo://CDS.VizieR/J/ApJ/780/59
- Title:
- The Araucaria project: eclipsing binaries in SMC
- Short Name:
- J/ApJ/780/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a distance determination to the Small Magellanic Cloud (SMC) based on an analysis of four detached, long-period, late-type eclipsing binaries discovered by the Optical Gravitational Lensing Experiment (OGLE) survey. The components of the binaries show negligible intrinsic variability. A consistent set of stellar parameters was derived with low statistical and systematic uncertainty. The absolute dimensions of the stars are calculated with a precision of better than 3%. The surface brightness-infrared color relation was used to derive the distance to each binary. The four systems clump around a distance modulus of (m - M) = 18.99 with a dispersion of only 0.05 mag. Combining these results with the distance published by Graczyk et al. for the eclipsing binary OGLE SMC113.3 4007, we obtain a mean distance modulus to the SMC of 18.965+/-0.025 (stat.)+/-0.048 (syst.) mag. This corresponds to a distance of 62.1+/-1.9 kpc, where the error includes both uncertainties. Taking into account other recent published determinations of the SMC distance we calculated the distance modulus difference between the SMC and the Large Magellanic Cloud equal to 0.458+/-0.068 mag. Finally, we advocate {mu}_SMC_= 18.95+/-0.07 as a new "canonical" value of the distance modulus to this galaxy.
- ID:
- ivo://CDS.VizieR/V/152
- Title:
- The DEBCat detached eclipsing binary catalogue
- Short Name:
- V/152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detached eclipsing binary star systems are our primary source of measured physical properties of normal stars. I introduce DEBCat: a catalog of detached eclipsing binaries with mass and radius measurements to the 2% precision necessary to put useful constraints on theoretical models of stellar evolution. The catalog was begun in 2006, as an update of the compilation by Andersen (1991A&ARv...3...91A). It now contains over 195 systems (2017/10/10), and new results are added on appearance in the refereed literature.
- ID:
- ivo://CDS.VizieR/J/AJ/105/2291
- Title:
- The eclipsing binary EG Ser
- Short Name:
- J/AJ/105/2291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stromgren b,y photometry of the detached A-type eclipsing binary EG Serpentis was obtained. Combined with the radial velocity curves in Popper [PASP, 98, 1312 (1986)], it was used to determine anew the system's parameters using the Wilson-Devinney code. The age of the system is derived from a comparison with the Bertelli et al. [A&AS, 85, 845 (1990)] isochrones. Within the accuracy limits, the results are in accordance with expectations.
- ID:
- ivo://CDS.VizieR/J/ApJ/845/72
- Title:
- The factory & the beehive. III. PTFEB132.707+19.810
- Short Name:
- J/ApJ/845/72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Theoretical models of stars constitute the fundamental bedrock upon which much of astrophysics is built, but large swaths of model parameter space remain uncalibrated by observations. The best calibrators are eclipsing binaries in clusters, allowing measurement of masses, radii, luminosities, and temperatures for stars of known metallicity and age. We present the discovery and detailed characterization of PTFEB132.707+19.810, a P=6.0day eclipsing binary in the Praesepe cluster ({tau}~600-800Myr; [Fe/H]=0.14+/-0.04). The system contains two late-type stars (SpT_P_=M3.5+/-0.2; SpT_S_=M4.3+/-0.7) with precise masses (M_p_=0.3953+/-0.0020M_{sun}_; M_s_=0.2098+/-0.0014M_{sun}_) and radii (R_p_=0.363+/-0.008R_{sun}_; R_s_=0.272+/-0.012R_{sun}_). Neither star meets the predictions of stellar evolutionary models. The primary has the expected radius but is cooler and less luminous, while the secondary has the expected luminosity but is cooler and substantially larger (by 20%). The system is not tidally locked or circularized. Exploiting a fortuitous 4:5 commensurability between Porb and P_rot,prim_, we demonstrate that fitting errors from the unknown spot configuration only change the inferred radii by <~1%-2%. We also analyze subsets of data to test the robustness of radius measurements; the radius sum is more robust to systematic errors and preferable for model comparisons. We also test plausible changes in limb darkening and find corresponding uncertainties of ~1%. Finally, we validate our pipeline using extant data for GU Boo, finding that our independent results match previous radii to within the mutual uncertainties (2%-3%). We therefore suggest that the substantial discrepancies are astrophysical; since they are larger than those for old field stars, they may be tied to the intermediate age of PTFEB132.707+19.810.
