- 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.
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- 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/AJ/140/319
- Title:
- BVR light curves of NGC 6026 and 6337
- Short Name:
- J/AJ/140/319
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Close-binary central stars of planetary nebulae (CSPNe) provide an opportunity to explore the evolution of PNe, their shaping, and the evolution of binary systems undergoing a common-envelope phase. Here, we present the results of time-resolved photometry of the binary central stars (CSs) of the PNe NGC 6026 and NGC 6337 as well as time-resolved spectroscopy of the CS of NGC 6026. The results of a period analysis give an orbital period of 0.528086(4) days for NGC 6026 and a photometric period of 0.1734742(5) days for NGC 6337.
- 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/PAZh/23/341
- Title:
- BVR observations of SS 433
- Short Name:
- J/PAZh/23/341
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric BVR photometry of SS 433 performed between 1988 and 1990 at Mt. Maidanak is presented.
- ID:
- ivo://CDS.VizieR/J/A+A/454/179
- Title:
- BVR phot. of Basel 11b, King 14, Czernik 43
- Short Name:
- J/A+A/454/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To progress in galactic studies based on open clusters, e.g. cluster formation rate or kinematical properties, one needs to improve the number of open clusters observed. However, only half of the 1700 known galactic open clusters have been properly observed so far, making any statistical investigation insignificant, especially at larger distances from the Sun. We study marginally investigated or neglected open clusters with Bessell CCD BVR photometry, whose data were used to fit isochrones to the individual color-magnitude diagrams. We examined the galactic clusters Basel 11b, King 14 and Czernik 43, the last being observed for the first time to this extent. As well as a careful comparison to available photometry, their parameters such as age, interstellar reddening, distance and apparent diameter were determined. The obtained cluster properties were verified by near infrared 2MASS data. The three investigated intermediate age clusters are all located in the galactic disk with distances between 1.8 and 3.0kpc from the Sun.
- ID:
- ivo://CDS.VizieR/J/A+A/436/117
- Title:
- BVR photometry in N214C
- Short Name:
- J/A+A/436/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the Large Magellanic Cloud HII region N 214C using imaging and spectroscopy obtained at the ESO New Technology Telescope. On the basis of the highest resolution images so far obtained of the OB association LH 110, we show that the main exciting source of the HII region, Sk -71 51, is in fact a tight cluster of massive stars consisting of at least 6 components in an area ~4" wide. Spectroscopic observations allow us to revise the spectral type of the main component (#17) to O2V((f*))+OB, a very rare, hot type. We also classify several other stars associated with N 214C and study the extinction and excitation characteristics of the HII region. Moreover, we obtain BVR photometry and astrometry of 2365 stars and from the corresponding color-magnitude diagram study the stellar content of N 214C and the surrounding LH 110. Furthermore, we discover a striking compact blob of ionized gas in the outer northern part of N 214C. A spherical structure of ~5", in radius (~1.3pc), it is split into two lobes by absorbing dust running diametrically through its center. We discuss the possible nature of this object.
