- ID:
- ivo://CDS.VizieR/J/A+A/465/943
- Title:
- BVI and RV curves of 5 eclipsing binaries
- Short Name:
- J/A+A/465/943
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We detected tertiary components of close binaries from spectroscopy and light curve modelling, investigated the light-travel time effect and the possibility of magnetic activity cycles, measured mass ratios for unstudied systems, and derived absolute parameters. We carried out new photometric and spectroscopic observations of five bright close eclipsing binaries, predominantly in the southern skies. We obtained full Johnson BV light curves, which were modelled with the Wilson-Devinney code. Radial velocities were measured with the cross-correlation method using IAU radial velocity standards as spectral templates. Period changes were studied with the O-C method, utilising published epochs of minimum light (XY Leo) and ASAS photometry (VZ Lib). For three objects (DX Tuc, QY Hya, V870 Ara), absolute parameters have been determined for the first time. We spectroscopically detected the tertiary components in XY Leo and VZ Lib and discovered one in QY Hya. For XY Leo we updated the light-time effect parameters and detected a secondary periodicity of about 5100d in the O-C diagram that may hint at the existence of short-period magnetic cycles. A combination of recent photometric data shows that the orbital period of the tertiary star in VZ Lib is likely to be over 1500d. QY Hya is a semi-detached X-ray active binary in a triple system with K and M-type components, while V870 Ara is a contact binary with the third smallest spectroscopic mass ratio for a W UMa star to date. Being close to the theoretical minimum for contact binaries, this small mass ratio suggests that V870 Ara has the potential of constraining evolutionary scenarios of binary mergers. The inferred distances to these systems are compatible with the Hipparcos parallaxes.
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- ID:
- ivo://CDS.VizieR/J/A+A/539/A139
- Title:
- BVIc light curves of SZ Cam
- Short Name:
- J/A+A/539/A139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic and photometric analysis of the multiple system and early-type eclipsing binary SZ Cam (O9 IV + B0.5 V), which consists of an eclipsing SB2 pair of orbital period P=2.7-days in a long orbit (~55yrs) around a non-eclipsing SB1 pair of orbital period P=2.8-days. We have reconstructed the spectra of the individual components of SZ Cam from the observed composite spectra using the technique of spectral disentangling. We used them together with extensive and accurate BV IC CCD photometry to obtain an orbital solution. Our photometry revealed the presence of a beta Cep variable in the SZ Cam hierarchical system, probably located within the non-eclipsing SB1 pair. The pulsation period is 0.33265+/-0.00005-days and the observed total amplitude in the B band is 0.0105+/-0.0005mag. NLTE analysis of the disentangled spectra provided atmospheric parameters for all three components, consistent with those derived from orbital solution.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1596
- Title:
- BVI photometric variability survey of M3
- Short Name:
- J/AJ/129/1596
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a three-band (BVI) variability survey of the globular cluster M3. This is the first three-band survey of the cluster using modern image subtraction techniques. Observations were made over nine nights in 1998 on the 1.2m telescope at the F. L. Whipple Observatory in Arizona. We present photometry for 180 variable stars in the M3 field, 12 of which are newly discovered. New discoveries include six SX Phoenicis-type variables that all lie in the blue straggler region of the color-magnitude diagram, two new first-overtone RR Lyrae variables, a candidate multimode RR Lyrae variable, a detached eclipsing binary, and two unclassified variables. We also provide revised periods for 52 of the 168 previously known variables that we observe.
- ID:
- ivo://CDS.VizieR/J/AcA/48/563
- Title:
- BVI photometry of OGLE SMC eclipsing binaries
- Short Name:
- J/AcA/48/563
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalog of 1459 eclipsing binary stars detected in the central 2.4 square degree area of the Small Magellanic Cloud during the OGLE-II microlensing search. The sample includes objects brighter than I~20mag with periods ranging from about 0.3 to 250 days. The average completeness of the catalog is about 80%. Statistics of the entire sample and well detached systems, suitable for distance determination, are also presented.
- ID:
- ivo://CDS.VizieR/J/AJ/138/680
- Title:
- BVI TX Cnc light curves
- Short Name:
- J/AJ/138/680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present B-, V-, and I-band CCD photometry of the W UMa-type binary system TX Cnc, which is a member star of the Praesepe open cluster. Based on the observations, new ephemeris and a revised photometric solution of the binary system were derived.
- ID:
- ivo://CDS.VizieR/J/A+A/483/263
- Title:
- BV light curve of V570 Per
- Short Name:
- J/A+A/483/263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The orbit and physical parameters of the previously unsolved double-lined eclipsing binary V570 Per are derived using Asiago Echelle high-resolution and high S/N spectroscopy, and B, V photo-electric photometry. Effective temperatures, gravities, rotational velocities, and metallicities of both components are also obtained from atmospheric chi^2^ analysis. The observed properties of V570 Per components are compared to available families of stellar evolutionary tracks, in particular to BaSTI models computed on purpose for exactly the observed masses and varied chemical compositions.
- ID:
- ivo://CDS.VizieR/J/A+A/452/959
- Title:
- BV light curve of V781 Tau
- Short Name:
- J/A+A/452/959
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze light curves of the W UMa type eclipsing binary V781 Tauri from three epochs and radial velocity curves from two epochs simultaneously, including previously unpublished B and V data. The overall time span is from 1983 to 2000 and the solution is done coherently in time (not phase) with five light curves and two sets of primary and secondary velocity curves. Minor systematic differences among the individual light curves are not large enough to undermine the value of a coherent solution that represents 18 years of observations. Times of minima confirm a period of 0.34491d and the general solution finds a small period change, dP/P, of (5.08+/-04)*10^-11^ that represents recent behavior. The eclipse timings cover the last half-century and find dP/P about four times smaller, corresponding to a period change time scale, P/(dP/dt) of about 6 million years. The system is over-contact with a filling factor of 0.205. The solution produces a temperature difference of about 260K between the components, an inclination of 65.9{deg}, and a mass ratio M_2_/M_1_=2.47. Separate solutions of the several light curves that incorporate dark spots find parameters that differ little from curve to curve. Absolute masses, luminosities, radii and the distance are derived, with luminosities and distance based on star 1 being of type G0V. The orbital angular momentum is compared with those of other W UMa type binaries and is normal. The star to star mass flow that one can infer from dP/dt is opposite to that expected from TRO (Thermal Relaxation Oscillator) theory, but pertains to a time span that is very short compared to the time scale of TRO oscillations.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/115
- Title:
- BV light curves of AU Ser
- Short Name:
- J/A+AS/131/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the Table 1 shown are the Heliocentric Julian Days at the start and at the end of the observation runs and the numbers of the observations for each color. Since the observations in 1991 have been published in Li et al. (1992IBVS.3802....1L), only those in 1992 and 1995 are listed in Table 2a and 2b for yellow and blue light respectively, where the Heliocentric Julian Days and the magnitude differences(the variable minus the comparison) are given. The normal points producing the light curves in Fig. 2 can found in Table 3 through 5.
- ID:
- ivo://CDS.VizieR/J/AJ/134/642
- Title:
- BV light curves of BB Pegasi
- Short Name:
- J/AJ/134/642
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based photometry of the low-temperature contact binary BB Peg. We collected all the times of mid-eclipse available in the literature and combined them with those obtained in this study.
- ID:
- ivo://CDS.VizieR/J/A+A/415/283
- Title:
- BV light curves of NN Vir
- Short Name:
- J/A+A/415/283
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric BV light curves of the recently discovered eclipsing binary NN Vir were studied for the first time to derive the physical parameters of the system. The light curves were obtained at the Ankara University Observatory during three nights in May, 2002. The solutions made by using Djurasevic's inverse problem method describe the NN Vir system as a high overcontact configuration (f_over_~58%) with a relatively small temperature differences between the components ({Delta}T=T_h_-T_c_~160K). These solutions suggest a significant mass and energy transfer from the more massive primary onto the less massive secondary. The hot area on the less massive star, near the neck region, can be taken as a consequence of this mass and energy exchange between the components through the connecting neck of the common envelope.
