- ID:
- ivo://CDS.VizieR/J/A+A/492/171
- Title:
- VIc light curves of NGC 6791 V20
- Short Name:
- J/A+A/492/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We wish to determine accurate ages for open clusters and use this, in conjunction with colour-magnitude diagrams, to constrain models of stellar structure and evolution. The detached eclipsing binary V20 in the old, metal-rich ([Fe/H]=+0.40) open cluster NGC6791 is studied in order to determine highly accurate masses and radii of its components. This allows the cluster age to be established with high precision, using isochrones in the mass-radius diagram. Methods. We employ high-resolution UVES spectroscopy of V20 to determine the spectroscopic orbit and time-series V, Ic photometry to obtain the photometric elements.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/839/52
- Title:
- Vi' LCs and RVs of the EB star TYC 5227-1023-1
- Short Name:
- J/ApJ/839/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The orbit and physical parameters of the previously unsolved double-lined eclipsing binary Tyc 5227-1023-1, discovered during the search for RR Lyr variable candidate members of the Aquarius stream, are derived using high-resolution echelle spectroscopy and V,i' photometry. A synthetic spectral analysis of both components has been performed, yielding metallicity [M/H]=-0.63+/-0.11 for both stars and a temperature for the secondary that is in close agreement with the one from the orbital solution, while the temperature of the primary is determined from photometry (T_1_=6350K). The masses and radii (M_1_=0.96+/-0.02, M_2_=0.84+/-0.01M_{sun}_, R_1_=1.39+/-0.01, R_2_=0.98+/-0.01R_{sun}_) reveal that both stars have already slightly evolved away from the main-sequence band, having an age of about 7Gyr, and the results of the synthetic spectral analysis support the claim of corotation with the orbital motion. The radial velocity of the system is -60+/-2km/s, while its distance, computed from orbital parameters and the derived reddening E_B-V_=0.053, is 496+/-35pc. Even though Tyc 5227-1023-1 was initially treated as a possible member of the Aquarius stream, the results presented here disagree with reported values for this ancient structure and suggest a likely membership of the thick disk.
- ID:
- ivo://CDS.VizieR/J/AcA/61/103
- Title:
- VI light curves of LMC eclipsing binaries
- Short Name:
- J/AcA/61/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 26121 visually inspected eclipsing binary stars identified in the Large Magellanic cloud during the third phase of the Optical Gravitational Lensing Experiment. the sample is limited to the out-of-eclipse brightness I<20mag. The catalog consist mostly of detached eclipsing binaries - ellipsoidal variables were not included.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2954
- Title:
- VI light curves of Sand 986 in M67
- Short Name:
- J/AJ/126/2954
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have discovered that the star S986 in the old open cluster M67 has detectable total eclipses of depth 0.08mag for the primary eclipse and 0.011mag for the secondary eclipse (in I only). We confirm the detection of a third star in spectra contributing (11.5+/-1.5)% of the total light in V band. The radial velocity of the third star indicates that it is a cluster member, but it is unclear whether it is physically associated with the eclipsing binary.
- ID:
- ivo://CDS.VizieR/J/A+A/550/A93
- Title:
- VI light curves of V383 Sco
- Short Name:
- J/A+A/550/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The system V383 Sco was discovered to be an eclipsing binary star at the beginning of the twentieth century. This system has one of the longest orbital periods known (13.5yr) and was initially classified as a zeta Aur-type eclipsing variable. It was then forgotten about for decades, with no progress made in understanding it. This study provides a detailed look at the system V383 Sco, using new data obtained before, during and after the last eclipse, which occurred in 2007/8. There was a suspicion that this system could be similar to eclipsing systems with extensive dusty disks like EE Cep and epsilon Aur. This and other, alternative hypotheses are considered here. The All Sky Automated Survey (ASAS-3) V and I light curves have been used to examine apparent magnitude and colour changes. Low- and high- resolution spectra have been obtained and used for spectral classification, to analyse spectral line profiles, as well as to determine the reddening, radial velocities and the distance to the system. The spectral energy distribution (SED) was analysed using all available photometric and spectroscopic data. Using our own original numerical code, we performed a very simplified model of the eclipse, taking into account the pulsations of one of the components. The low-resolution spectrum shows apparent traces of molecular bands, characteristic of an M-type supergiant. The presence of this star in the system is confirmed by the SED, by a strong dependence of the eclipse depth on the photometric bands, and by the nature of pulsational changes. The presence of a very low excitation nebula around the system has been inferred from [OI] 6300{AA} emission in the high-resolution spectrum. Analysis of the radial velocities, reddening, and period-luminosity relation for Mira-type stars imply a distance to the V383 Sco system of 8.4+/-0.6kpc. The distance to the nearby V381 Sco is 6.4+/-0.8kpc. The very different and oppositely directed radial velocities of these two systems (89.8km/s vs -178.8km/s) seem to be in agreement with a bulge/bar kinematic model of the Galactic centre and inconsistent with purely circular motion. Conclusions. We have found strong evidence for the presence of a pulsating M-type supergiant in the V383 Sco system. This supergiant periodically obscures the much more luminous F0 I-type star, causing the deep (possibly total) eclipses which vary in duration and shape.
- ID:
- ivo://CDS.VizieR/J/A+A/282/137
- Title:
- Vilnius Photometry of HD211853
- Short Name:
- J/A+A/282/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometric observations of the Wolf-Rayet binary HD 211853 are presented. They were obtained with the 1-m reflector of the Institute of Theretical Physics and Astrophysics of the Lithuanian Academy of Sciences on Maydanak Mountain in Uzbekistan during 15 nights in August 1991; a single-channel photometer equipped with the Vilius photometric system filters was used. The period search routine confirms the period of 6.6884 days for pair A. For pair B, a new corrected ephemeris (T0 = 2443689.16, P = 3.4696 days) is determined. This ephemeris allows to present light minima of all available photometric data in the same phase. Moreover, they are in good accordance with the absorption lines radial velocity residuals of Hiltner (1945ApJ...101..356H) and Massey (1981ApJ...244..157M). It is shown that the third possible period of 2.34607 days found by Panov & Seggewiss (1990A&A...227..117P) is an alias from the half period of approximately 3.47 days.
- ID:
- ivo://CDS.VizieR/J/AJ/123/279
- Title:
- VI Photometry and Variables in NGC 3201
- Short Name:
- J/AJ/123/279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Globular Cluster NGC 3201 was monitored for the existence of variable stars with 16.5<V<20 and 0.2days<period<5days. The files v*.dat contain time-series photometry data in V and I for the 14 variables detected in the field of NGC 3201. Only V6 (a blue straggler contact binary) is a member of the cluster. Due to its low-latitude position, interstellar extinction is present across the field of the cluster. The file phot.dat contains VI photometry data on the monitored stars. These data are NOT corrected for extinction. The variables V7, V8, and V9 were discovered during a follow-up observing run with a different telescope and therefore do not lie in the field covered by phot.dat. Variables V1-V9 are contact system eclipsing binaries, V10 is an RR Lyrae, V11 a semi-detached Algol type binary, V12 a detached binary system, and V13 and V14 are unclassified variable systems.
- ID:
- ivo://CDS.VizieR/J/other/NewA/38.50
- Title:
- VIr light curves of GK Aqr
- Short Name:
- J/other/NewA/38.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We made the first VRI CCD light curves of the short-period contact eclipsing binary GK Aqr, which was observed on October 5 and 8, 2013 at Xinglong station of National Astronomical Observatories, China. The ephemeris of GK Aqr was calculated based on our two newly obtained minima and the minima that other observers obtained previously. We discovered that the orbital period of GK Aqr exhibits an increasing trend of dP/dt=2.8(0.1)x10^-7^days/year by means of fitting the O-C values of the minima. This phenomenon might be explained by mass transfer from the primary (less massive) component to the secondary (more massive) one. With the updated Wilson & Devinney (1971ApJ...166..605W) program, we obtained the photometric orbital parameters for the first time. Using our parameters, we also successfully explained the light curve obtained from the All Sky Automated Survey data. In the end, we concluded that GK Aqr is a near contact binary with a low contact factor of 5.2%. As the mass transfer continues, GK Aqr could become a contact system and evolve into an over-contact system.
- ID:
- ivo://CDS.VizieR/J/AJ/157/171
- Title:
- Visual analysis and demographics of Kepler TTVs
- Short Name:
- J/AJ/157/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We visually analyzed the transit timing variation (TTV) data of 5930 Kepler Objects of Interest (KOIs) homogeneously. Using data from Rowe et al. (2014, J/ApJ/784/45) and Holczer et al. (2015, J/ApJ/807/170; 2016, J/ApJS/225/9), we investigated TTVs for nearly all KOIs in Kepler's Data Release 24 catalog. Using TTV plots, periodograms, and phase-folded quadratic plus sinusoid fits, we visually rated each KOI's TTV data in five categories. Our ratings emphasize the hundreds of planets with TTVs that are weaker than the ~200 that have been studied in detail. Our findings are consistent with statistical methods for identifying strong TTVs, though we found some additional systems worth investigation. Between about 3-50 days and 1.3-6 Earth radii, the frequency of strong TTVs increases with period and radius. As expected, strong TTVs are very common when period ratios are near a resonance, but there is not a one-to-one correspondence. The observed planet-by-planet frequency of strong TTVs is only somewhat lower in systems with one or two known planets (7%+/-1%) than in systems with three or more known planets (11%+/-2%). We attribute TTVs to known planets in multitransiting systems but find ~30 cases where the perturbing planet is unknown. Our conclusions are valuable as an ensemble for learning about planetary system architectures and individually as stepping stones toward more-detailed mass-radius constraints. We also discuss Data Release 25 TTVs, investigate ~100 KOIs with transit duration and/or depth variations, and estimate that the Transiting Exoplanet Survey Satellite will likely find only ~10 planets with strong TTVs.
- ID:
- ivo://CDS.VizieR/J/other/NewA/36.32
- Title:
- V441 Lac VRI light curves
- Short Name:
- J/other/NewA/36.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first multi-color VRI CCD light curves of a short-period eclipsing binary star v441 Lac in this paper. We obtained our light curves on Oct. 4 and 8, 2013 at Xinglong station of National Astronomical Observatories, China. We updated the ephemeris of V441 Lac based on three new minima derived by our new observational data together with previously available light curve minima. By fitting the O-C (observed minus calculated) values of the minima, we found that the orbital period of V441 Lac exhibits an increasing trend of View the dP/dt=5.67(0.35)x10^-7^days/year, which might be explained by mass transfer from the secondary component to the primary one, or angular momentum exchange by magnetic activities. We also obtained the photometric orbital parameters with the Wilson & Devinney program. Our final result shows that the V441 Lac system is a semi-detached binary with the secondary component filling roche lobe.
