- ID:
- ivo://CDS.VizieR/J/other/NewA/53.39
- Title:
- BVRI light curves of GR Boo
- Short Name:
- J/other/NewA/53.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BVRI light curves with complete phase coverage for the short-period (p=0.377day) eclipsing binary star GR Boo. We carried out the observations using the SARA 90cm telescope located at Kitt Peak National Observatory. We obtained six new light curve minimum times. By fitting all of the available O-C minimum times, we obtained an updated ephemeris that shows the orbital period of GR Boo is decreasing at a rate of dP/dt=-2.36x10^-7^days/year. This decrease in its period can be explained by either mass transfer from the more massive component to the less massive one, or angular momentum exchange due to magnetic activities. We also obtained a set of revised orbital parameters using the Wilson & Devinney program. And finally, we concluded that GR Boo is a contact binary with a dark spot.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/406/2559
- Title:
- BVRI light curves of GSC2314-0530
- Short Name:
- J/MNRAS/406/2559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CD photometric observations in VRI colours and spectroscopic observations of the newly discovered eclipsing binary GSC 2314-0530 (NSVS 6550671) with dMe components and a very short period of P=0.192636d are presented. The simultaneous light-curve solution and radial velocity solution allow us to determine the global parameters of GSC 2314-0530: T1=3735K; T2=3106K; M1=0.51M_{sun}_; M2=0.26M_{sun}_; R1=0.55R_{sun}_; R2=0.29R_{sun}_; L1=0.053L_{sun}_; L2=0.007L_{sun}_; i=72.5{swg}; a=1.28R_{sun}_; d=59pc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/407/497
- Title:
- BVRI light curves of KZ Pav
- Short Name:
- J/MNRAS/407/497
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from analysing new spectroscopic and photometric observations of the KZ Pav (IDS 20490-7048 A-BC) multiple system. High-resolution spectra were taken at the Mt John University Observatory in 2007 and 2008. Radial velocities for the close binary were determined from cross-correlation and spectral disentangling methods.
- ID:
- ivo://CDS.VizieR/J/AJ/157/3
- Title:
- BVRI light curves of the binary QS Vir
- Short Name:
- J/AJ/157/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed the post-common-envelope eclipsing binary with a white dwarf component, QS Vir, using the 1.88 m telescope of Kotammia Observatory in Egypt. The new observations were analyzed together with all multicolor light curves available online (sampling a period of 25 yr), using a full-feature binary system modeling software based on Roche geometry. This is the first time complete photometric modeling was done with most of these data. QS Vir is a detached system, with the red dwarf component underfilling its Roche lobe by a small margin. All light curves feature out-of-eclipse variability that is associated with ellipsoidal variation, mutual irradiation and irregularities in surface brightness of the tidally distorted and magnetically active red dwarf. We tested models with one, two, and three dark spots and found that one spot is sufficient to account for the light curve asymmetry in all data sets, although this does not rule out the presence of multiple spots. We also found that a single spotted model cannot fit light curves observed simultaneously in different filters. Instead, each filter requires a different spot configuration. To thoroughly explore the parameter space of spot locations, we devised a grid-search procedure and used it to find consistent solutions. Based on this, we conclude that the dark spot responsible for light curve distortions has been stable for the past 15 yr, after a major migration that happened between 1993 and 2002, possibly due to a flip-flop event.
- ID:
- ivo://CDS.VizieR/J/AJ/145/9
- Title:
- BVRI light curves of the early-type binary V382 Cyg
- Short Name:
- J/AJ/145/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze photometric and spectroscopic data and study the orbital period of the early-type interacting binary system V382 Cyg by using all the available data. We obtain a simultaneous light and radial velocity curve solution. The derived physical parameters of the primary and secondary stellar components are M_1_=27.9(5)M_{sun}_, M_2_=20.8(4)M_{sun}_, R_1_=9.7(2)R_{sun}_, R_2_=8.5(2)R_{sun}_, log(L_1_/L_{sun}_)=5.152(20), and log(L_2_/L_{sun}_)=4.954(19) while the separation of the components is a=23.4R_{sun}_. Newly obtained parameters yield the distance of the system to be 1466(76)pc. Analyses of the mid-eclipse times indicate a period increase of dP/dt=4.2(1)x10^-7^days/yr that can be interpreted in terms of the high-mass transfer (dM/dt=6.1(5)x10^-6^M_{sun}_/yr) from the less massive component to the more massive component. Finally, we model the evolution of the components using non-conservative codes and discuss the results obtained. The age of the binary system is estimated to be 3.85Myr.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2696
- Title:
- BVRI light curves of Westerlund 1 stars
- Short Name:
- J/AJ/133/2696
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the first optical variability study of the Westerlund 1 super star cluster in search of massive eclipsing binary systems. A total of 129 new variable stars have been identified, including the discovery of 4 eclipsing binaries that are cluster members, 1 additional candidate, 8 field binaries, 19 field delta Scuti stars, 3 field W UMa eclipsing binaries, 13 other periodic variables, and 81 long-period or nonperiodic variables. These include the known luminous blue variable, the B[e] star, 11 Wolf-Rayet stars, several supergiants, and other reddened stars that are likely members of Westerlund 1. The bright X-ray source corresponding to the Wolf-Rayet star WR 77o (B) is found to be a 3.51 day eclipsing binary. The discovery of a reddened detached eclipsing binary system implies the first identification of main-sequence stars in Westerlund 1.
- ID:
- ivo://CDS.VizieR/J/AJ/149/48
- Title:
- BVRI light curves of ZZ Eri
- Short Name:
- J/AJ/149/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Complete Bessel BVRI light curves of ZZ Eri [2MASSJ04130109-1044545, HV 6280, NSVS 14888164; IRCS position 04:13:01.10-10:44:54.5; V=13.9-14.4-15.0] are observed and analyzed. The system is a southern pre-contact W UMa binary. Its light curve has the appearance of an Algol (EA) light curve, however, it is made up of dwarf solar-type components with a period of only 0.4521days. Our 34year period study yields a sinusoidal fit or an increasing quadratic fit. The sinusoid may indicate that a third body is orbiting the close binary. The lower-limit mass of the third body is near that of the brown dwarf limit (0.095M_{sun}_). Also included is an improved ephemeris, a mass ratio search, and a simultaneous BVRI Wilson-Devinney solution.
- ID:
- ivo://CDS.VizieR/J/AJ/142/99
- Title:
- BVRI observations of TZ Boo
- Short Name:
- J/AJ/142/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric BVRI observations of the puzzling W UMa type binary star, TZ Bootis, are presented from our observations in 2010. By using the updated version of the Wilson-Devinney code, the first modern photometric solution is deduced from new photometric observations and published spectroscopic data.
- ID:
- ivo://CDS.VizieR/J/AJ/130/234
- Title:
- BVRI photometry and radial velocities of AV Del
- Short Name:
- J/AJ/130/234
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new spectroscopic and BVRI photometric observations of the double-lined eclipsing binary AV Del (period=3.85days) conducted over six observing seasons.
- ID:
- ivo://CDS.VizieR/J/AJ/144/37
- Title:
- BVRI photometry of the eclipsing binary BS Vul
- Short Name:
- J/AJ/144/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed study of the close eclipsing binary BS Vulpeculae. Although it is relatively bright (V: 10.9-11.6mag) and belongs to short-periodic variable stars (P=0.48days), it is rather neglected. To perform a thorough period analysis, we collected all available photometric observations that span the time interval of 1898-2010. Observations include archive photographic plate measurements and visually determined eclipse minima timings done in 1979-2003, which were later shown to be biased to accommodate the existing linear ephemeris. Applying our own direct period analysis we found a well-defined shortening of the orbital period of dP/dt=-6.70(17)x10^-11^=-2.11(6)ms/yr, which implies a continual mass flow from the primary to the secondary component. Using the 2003 version of the Wilson-Van Hamme code, our new complete BV(IR)_C_ light curves were analyzed and the physical parameters of the system were derived. We found that BS Vul is a near contact binary system with the primary component filling its critical Roche lobe. The luminosity enhancement on the left shoulder of the secondary minimum shown in the light curves can be explained as a result of a persistent hot spot on the secondary due to the mass transfer from the primary component to the secondary one and heating the facing hemisphere of the secondary component, which is consistent with our result of period analysis. With the period decrease, BS Vul will evolve toward the contact phase. It is another good observational example as predicted by the theory of thermal relaxation oscillations.
