scholarly journals The Photometric Investigation of V921 Her Using the Lunar-Based Ultraviolet Telescope of Chang’e-3 Mission

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao Zhou ◽  
Sheng-Bang Qian ◽  
Jia Zhang ◽  
Lin-Jia Li ◽  
Qi-Shan Wang
Keyword(s):  
Binary System ◽  
Thermal Contact ◽  
Primary Star ◽  
Light Minimum ◽  
Evolutionary Scenario ◽  
Total Luminosity ◽  
Massive Component ◽  
Contact Binary ◽  
Photometric Investigation ◽  
First Time

The light curve of V921 Her in ultraviolet band observed by the Lunar-based Ultraviolet Telescope (LUT) is analyzed by the Wilson-Devinney code. Our solutions conclude that V921 Her is an early type marginal contact binary system with an additional close-in component. The binary system is under poor thermal contact with a temperature difference of nearly 700 K between the two components. The close-in component contributes about 19% of the total luminosity in the triple system. Combining the radial velocity study together with our photometric solutions, the mass of the primary star and secondary one is calculated to beM1=1.784  (±0.055)M⊙,M2=0.403  (±0.012)M⊙. The evolutionary scenario of V921 Her is discussed. All times of light minimum of V921 Her available in the bibliography are taken into account and theO-Ccurve is analyzed for the first time. The most probable fitting results are discussed in the paper, which also confirm the existence of a third component (P3=10.2year) around the binary system. The period of V921 Her is also undergoing a continuously rapid increase at a rate ofdP/dt=+2.79×10-7  day·year-1, which may be due to mass transfer from the less massive component to the more massive one.

Photometric investigation of the evolved contact binary system DN Aur

1996 ◽  
Vol 246 (2) ◽  
pp. 291-298 ◽  
Author(s):  
S. N. Goderya ◽  
K. C. Leung ◽  
E. G. Schmidt
Keyword(s):  
Binary System ◽  
Contact Binary ◽  
Photometric Investigation

scholarly journals V606 Cen: A Newly Formed Massive Contact Binary in a Hierarchical Triple System

2022 ◽  
Vol 924 (1) ◽  
pp. 30
Author(s):  
F.-X. Li ◽  
W.-P. Liao ◽  
S.-B. Qian ◽  
E. Fernández Lajús ◽  
J. Zhang ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Triple System ◽  
Continuous Light ◽  
Close Binary ◽  
Massive Component ◽  
Cyclic Oscillation ◽  
Contact Binary ◽  
Period Decrease ◽  
First Time ◽  
Linear Period

Abstract V606 Centauri (V606 Cen) is an early B-type close binary with an orbital period of 1.4950935 days, and its complete light curves are very difficult to observe on the ground. By analyzing the continuous light curve obtained by TESS, we found that it is a marginal contact binary with a very low fill-out factor of about 2%. The O − C diagram of V606 Cen is constructed for the first time based on 118.8 yr of eclipse times. The O − C diagram has been found to show a downward parabolic change together with a cyclic oscillation with a semiamplitude of 0.0545 days and a period of 88.3 yr. The downward parabolic variation reveals a linear period decrease at a rate of dP/dt = −2.08 × 10−7 days yr−1 that can be explained by the mass transfer from the more massive component to the less massive one. Both the marginal contact configuration and the continuous period decrease suggest that V606 Cen is a newly formed contact binary via Case A mass transfer. The cyclic change in the O − C diagram can be explained by the light-travel time effect via the presence of a third body. The lowest mass of the tertiary companion is determined to be M 3 = 4.51 (±0.43) M ⊙ and the tertiary is orbiting around the central eclipsing binary in a nearly circular orbit (e = 0.33). All of the results indicate that V606 Cen is a newly formed massive contact binary in a hierarchical triple system.

Studies on the equatorial spot of G-type contact binary UV Lyn

2021 ◽  
Author(s):  
Jingjing Wang ◽  
Bin Zhang ◽  
Linqiao Jiang
Keyword(s):  
Magnetic Activity ◽  
The Past ◽  
Photometric Observations ◽  
Massive Component ◽  
Type Contact ◽  
Contact Binary ◽  
Periodic Trend ◽  
Short Time ◽  
First Time ◽  
Magnitude Difference

Abstract New CCD photometric observations of G-type contact binary UV Lyn were obtained in 2006 and 2020, when the light curves (LCs) show positive O'Connell effect and negative O'Connell effect, especially. From the previous studies, the LCs by other ground-based telescope are variable from 1973 to 2020, particularly the magnitude difference between the two maxima. These phenomena indicate that the component is active in the past 47 years. In addition, under the monitoring of the space telescope of Transiting Exoplant Survey Satellite (TESS) from January to March in 2020, we fortunately find the continuous variations of O'Connell effect in every circle for the first time. The analysis also shows that in a short time, the positive O'Connell effect has been transformed into the negative one, which proves that there are stronger magnetic activities on the surface of the component. By using the Wilson-Devinney code with a spot model, these photometric solutions confirm UV Lyn is a shallow W-subtype contact binary with a cool equatorial spot on the less massive component. The successive variability of O'Connell effect possibly result from one equatorial cool spot shifting gradually along with time. We also investigate its \emph{O-C} curve from these continuous LCs, there is not obvious variation in such short time. while, the O’Connell effect as the indicator of the magnetic activity are possibly undergoing a periodic trend of a period of nearly 38 days. Comparing \emph{O-C} curve, we could find there is not relation between the period variation and magnetic activity.

scholarly journals New Photometric Investigation of the Solar-Type Shallow-Contact Binary HH Bootis

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Jia-jia He ◽  
Jing-jing Wang
Keyword(s):  
Light Curves ◽  
Mass Ratio ◽  
Third Body ◽  
Light Minimum ◽  
Short Period ◽  
Cyclic Oscillation ◽  
Type Contact ◽  
Contact Binary ◽  
Solar Type ◽  
Photometric Investigation

The short-period solar-type contact binary HH Boo was monitored photometrically for about 8 years. It is found that the CCD light curves in the B, V, R, and I bands obtained in 2010 are symmetric, while the multicolor light curves observed in 2011 and 2012 by several investigators showed a positive O’Connell effect where the maxima following the primary minima are higher than the other ones. This indicates that the light curve of the solar-type contact binary is variable. By analyzing our multicolor light curves with the Wilson-Devinney code (W-D code), it is confirmed that HH Boo is a W-type shallow-contact binary system with a mass ratio of q = 1.703(31) and a degree of contact factor of f = 12.86%(0.73%). By including 109 new determined times of light minimum together with those compiled from the literature, it is detected that the O-C diagram shows a cyclic oscillation with a period of T3 = 6.58(11) yr and an amplitude of A3 = 0.0018(1) d. The cyclic change may reveal the presence of an extremely cool third body orbiting the central binary.

scholarly journals An Extensive Photometric Investigation of the W UMa System DK Cyg

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
M. M. Elkhateeb ◽  
M. I. Nouh ◽  
E. Elkholy ◽  
B. Korany
Keyword(s):  
Binary System ◽  
Evolutionary Status ◽  
Evolutionary Models ◽  
Period Increase ◽  
System A ◽  
New Period ◽  
Contact Binary ◽  
Photometric Investigation ◽  
Photometric Solution

DK Cyg (P=0.4707) is a contact binary system that undergoes complete eclipses. All the published photoelectric data have been collected and utilized to reexamine and update the period behavior of the system. A significant period increase with rate of 12.590 × 10−11 days/cycle was calculated. New period and ephemeris have been calculated for the system. A long term photometric solution study was performed and a light curve elements were calculated. We investigated the evolutionary status of the system using theoretical evolutionary models.

scholarly journals Doppler Tomography in 2D and 3D of the X-ray Binary Cyg X-1 for June 2007

2011 ◽  
Vol 7 (S282) ◽  
pp. 201-202 ◽  
Author(s):  
O. I. Sharova ◽  
M. I. Agafonov ◽  
E. A. Karitskaya ◽  
N. G. Bochkarev ◽  
S. V. Zharikov ◽  
...  
Keyword(s):  
Binary System ◽  
Spectral Data ◽  
Inclination Angle ◽  
Tomographic Reconstruction ◽  
Orbital Plane ◽  
National Observatory ◽  
Doppler Tomography ◽  
X Ray ◽  
2D And 3D ◽  
First Time

AbstractThe 2D and 3D Doppler tomograms of X-ray binary system Cyg X-1 (V1357 Cyg) were reconstructed from spectral data for the line HeII 4686Å obtained with 2-m telescope of the Peak Terskol Observatory (Russia) and 2.1-m telescope of the Mexican National Observatory in June, 2007. Information about gas motions outside the orbital plane, using all of the three velocity components Vx, Vy, Vz, was obtained for the first time. The tomographic reconstruction was carried out for the system inclination angle of 45°. The equal resolution (50 × 50 × 50 km/s) is realized in this case, in the orbital plane (Vx, Vy) and also in the perpendicular direction Vz. The checkout tomograms were realized also for the inclination angle of 40° because of the angle uncertainty. Two versions of the result showed no qualitative discrepancy. Details of the structures revealed by the 3D Doppler tomogram were analyzed.

scholarly journals An Accretion-Disc Model for the Algol-Type Eclipsing Binary System AV Del

2011 ◽  
Vol 28 (1) ◽  
pp. 38-45 ◽  
Author(s):  
S. M. R. Ghoreyshi ◽  
J. Ghanbari ◽  
F. Salehi
Keyword(s):  
Binary System ◽  
Radial Velocity ◽  
Outer Radius ◽  
Accretion Disc ◽  
Physical Parameters ◽  
Primary Star ◽  
Eclipsing Binary ◽  
Disc Model ◽  
The Absolute

AbstractThis study inspects the light and radial-velocity curves of the eclipsing binary AV Del. In comparison with other studies already done, the study shows that the absolute elements, fundamental orbital and physical parameters of the system can be determined using the Wilson-Devinney code. Using these parameters, the configuration of the system is presented. Then, an accretion disc model for the system is introduced by using the shellspec code. The results indicate that AV Del is a semi-detached system in which an optically thick accretion disc is surrounding the primary star. The outer radius of the disc is 8.0 R⊙, corresponding to a distance of 1.1 R⊙ from the surface of the secondary. Also, the temperature of the disc is calculated to be T = 5700 K.

scholarly journals Variability of the Light Curves of the Close Binary GR Tauri

2002 ◽  
Vol 187 ◽  
pp. 337-338
Author(s):  
A. Yamasaki ◽  
M. Takeda ◽  
T. Yamauchi ◽  
G. Takada ◽  
S. Hattori
Keyword(s):  
Binary System ◽  
The State ◽  
Light Curves ◽  
Close Binary ◽  
Eclipsing Binary ◽  
Short Period ◽  
Contact Binary

AbstractVariability of the light curves of the short-period eclipsing binary system GR Tau (, almost-contact binary) is studied. It is found that GR Tau experienced both the state which is characterized by asymmetric light curves and the state characterized by symmetrical light curves.

The contact binary system YY Eri

1996 ◽  
Vol 246 (2) ◽  
pp. 229-242 ◽  
Author(s):  
E. Budding ◽  
C-H. Kim ◽  
O. Demircan ◽  
Z. Müyesseroğlu ◽  
K. Saijo ◽  
...  
Keyword(s):  
Binary System ◽  
Contact Binary
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