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- ID:
- ivo://CDS.VizieR/J/ApJ/877/75
- Title:
- BVRI photom. of DV Psc and known short-period EBs
- Short Name:
- J/ApJ/877/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using 27 sets of new multiband photometry light curves acquired from our long-term photometric campaign carried out in the last 5yr and high-resolution spectroscopic data from seven nights, we analyzed the physical mechanisms of period variation, starspot cycle, optical flares, and chromospheric activities of the eclipsing binary DV Psc. Our updated O-C diagram covering a period of approximately 20yr shows an oscillation in its orbital period. This variations might be caused by a third body with an orbital period of 14.58+/-0.28yr. There are two active regions of starspots at longitude belts of about 90{deg} and 270{deg}. We obtained its starspot cycles with periods of 3.60+/-0.03yr and 3.42+/-0.02yr at about 90{deg} and 270{deg}, respectively. Moreover, the magnitude difference of Max.I-Max.II shows cyclic oscillation of 5.15+/-0.01yr. During our decade long photometric campaign, we observed DV Psc a total of 326.4hr, detected 18 outbursts (12 of them have never been reported) with flare energies in the range of (6.62-1106.85)x10^24^J. The slope of the relationship between the phase of the max flare and spots is 0.842 +/-0.083, implying a correlation between spots and flares. We discovered evidence for a correlation between the rotation period and the activity cycle for the short-period eclipsing binaries. Our high-resolution spectroscopic observations of DV Psc show obvious emissions above continuum in the H{alpha} line and small self-reversal emissions of the CaII IRT lines.
- ID:
- ivo://CDS.VizieR/J/PASP/121/1366
- Title:
- BVR light curves of BX Peg
- Short Name:
- J/PASP/121/1366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on 2008 September. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-term brightness disturbance.
- ID:
- ivo://CDS.VizieR/J/AJ/146/35
- Title:
- BVR light curves of DZ Psc
- Short Name:
- J/AJ/146/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New multi-color photometry for the eclipsing binary DZ Psc was performed in 2011 and 2012 using the 85cm telescope at the Xinglong Station of the National Astronomical Observatories of China. Using the updated Wilson-Devinney (W-D) code, we deduced two sets of photometric solutions. The overcontact degree is f=89.7(+/-1.0)%, identifying DZ Psc as a deep, low mass ratio overcontact binary. The asymmetric light curves (i.e., LC_2_ in 2012) were modeled by a hot spot on the primary star. Based on all of the available light minimum times, we discovered that the orbital period of DZ Psc may be undergoing a secular period increase with a cyclic variation. The modulated period and semi-amplitude of this oscillation are P_mod_=11.89(+/-0.19)yr and A=0.0064(+/-0.0006)days, which may be possibly attributed to either cyclic magnetic activity or light-time effect due to the third body. The long-term period increases at a rate of dP/dt=+7.13(+/-0.17)*10^-7^days/yr, which may be interpreted as conserved mass transfer from the less massive component to the more massive one. With mass transferring, DZ Psc will finally merge into a rapid-rotation single star when J_spin_/J_orb_>1/3.
- ID:
- ivo://CDS.VizieR/J/A+A/537/A109
- Title:
- BVR light curves of GK Boo and AE For
- Short Name:
- J/A+A/537/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of late-type low-mass eclipsing binaries provides us with important information about the most common stars in the Universe. We obtain the first light curves and perform period analyses of two neglected eclipsing binaries GK Boo and AE For to reveal their basic physical properties. We performed both a period analysis of the times of the minima and a BVR light curve analysis. Many new times of minima for both the systems were derived and collected from the data obtained by automatic and robotic telescopes. This allowed us to study the long-term period changes in these systems for the first time. From the light curve analysis, we derived the first rough estimates of the physical properties of these systems.
- ID:
- ivo://CDS.VizieR/J/A+A/519/A78
- Title:
- BVR light curves of KR Com
- Short Name:
- J/A+A/519/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the detailed analysis of triple system KR Com with different observational techniques - photometry, interferometry, and period variation. The use of BVR photometry of the close-contact binary KR Com, which is the primary component of a triple system, helps us to better describe the properties of the components. The interferometric data obtained during the last 30 years sufficiently determine the visual orbit, but the use of minima timings of KR Com for the study of period variation together with the visual orbit is a novel approach in this system.
- ID:
- ivo://CDS.VizieR/J/PASP/130/C4201
- Title:
- BVR light curves of UZ Leo
- Short Name:
- J/PASP/130/C4201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric observations of UZ Leo were obtained between 2012 February and 2013 April, and on 2017 February. Its physical properties were derived from detailed analyses of our light curves and existing radial velocities. The results indicate that this system is a totally eclipsing A-subtype overcontact binary with both a high fill-out factor of 76% and a third light source contributing 12% light in the B bandpass, 10% in V, and 7% in R. The light residuals between observations and theoretical models are satisfactorily fitted by adopting a magnetic cool spot on the more massive primary star. Including our 12 measurements, a total of 172 eclipse times were used for ephemeris computations. We found that the orbital period of UZ Leo has varied due to a periodic oscillation superposed on an upward parabolic variation. The observed period increase at a rate of +3.49x10^-7^day/yr can be plausibly explained by some combination of non-conservative mass transfer from the secondary to the primary component and angular momentum loss due to magnetic braking. The period and semi-amplitude of the oscillation are about 139 years and 0.0225 days, respectively, which is interpreted as a light-time effect due to a third component with a mass of M_3_sini_3_=0.30M_\{sun}_. Because the third lights of 7%-12% indicate that the circumbinary object is very overluminous for its mass, it would possibly match a white dwarf, rather than an M-type main sequence.
- ID:
- ivo://CDS.VizieR/J/other/NewA/17.46
- Title:
- BVR light curves of V1191 Cyg
- Short Name:
- J/other/NewA/17.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of photometric and spectroscopic variation, and orbital period study of the late-type contact binary system V1191 Cyg. The system is found to be a contact binary system having strange configuration with very small mass ratio and short orbital period comparing with the other members of the same group. We determined a new set of stellar physical parameters for hot and cooler companion as M_h_=0.13(1)M_{sun}_, M_c_=1.29(8)M_{sun}_, R_h_=0.52(15)R_{sun}_, R_c_=1.31(18)R_{sun}_, L_h_=0.46(25)L_{sun}_, L_c_=2.71(80)L_{sun}_, and the separation between the components a=2.20(8)R_{sun}_ from the simultaneous solution of the light and radial velocity curves. Analyses of the mid-eclipses time of the system indicate a period increase of dP/dt=1.3(1)x10^-6^days/yr that can be interpreted in terms of the high mass transfer dM/dt=2.0(4)x10^-7^M_{sun}_/yr from the less massive component to the more massive one.
- ID:
- ivo://CDS.VizieR/J/AJ/149/62
- Title:
- BVR light curves of V508 Oph
- Short Name:
- J/AJ/149/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, new CCD photometric observations of V508 Oph obtained in 2009 and 2010 at the Xinglong Observatory are presented. From the new observations, six new times of minimum light were derived. The light curves were analyzed by using the 2003 version of the Wilson-Devinney program. It is found that the asymmetric light curves can be modeled by a hot spot on the secondary component. The degree of overcontact is 15.4%, implying that the system is a shallow-contact binary. Combining the new times of minimum light with the photoelectric and CCD data compiled from the database, we investigate its orbital period. The results show that the orbital period may be undergoing multiple changes: a long-term decrease at a rate of dP/dt=-(1.502+/-0.063)x10^-7^days/year, and a small periodic variation with a period of 24.27(+/-0.34) years. Since V508 Oph is an overcontact system and both components are late-type stars, we discuss the possible connection between the mass transfer, magnetic activity, the third body, and the orbital period changes.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1032
- Title:
- BVR photometry of BO CVn and SS Com
- Short Name:
- J/AJ/131/1032
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BO CVn and SS Com are two short-period W UMa-type binary stars with spectral types earlier than F5. In the present paper new CCD photometric light curves in B, V, and R bands of BO CVn and the first complete light curve in V band of SS Com are presented.
