scholarly journals A photometric study of the high-mass-ratio contact binary AV Puppis

2019 ◽  
Vol 19 (12) ◽  
pp. 174 ◽  
Author(s):  
Quan-Wang Han ◽  
Li-Fang Li ◽  
Deng-Kai Jiang
Keyword(s):  
High Mass ◽  
Photometric Study ◽  
Mass Ratio ◽  
Contact Binary

BVR photometric study of NSVS 2607629. A high mass-ratio W-type W UMa system

New Astronomy ◽  
2017 ◽  
Vol 51 ◽  
pp. 128-134 ◽  
Author(s):  
Birol Gürol ◽  
Raul Michel
Keyword(s):  
High Mass ◽  
Photometric Study ◽  
Mass Ratio

CSS J075415.6+191052 and NW Leo: two contact binaries at different evolutionary stages

2021 ◽  
Author(s):  
Xu-Dong Zhang ◽  
Shengbang Qian ◽  
Ergang Zhao ◽  
Qijun Zhi ◽  
Aijun Dong ◽  
...  
Keyword(s):  
Relaxation Oscillation ◽  
Thermal Relaxation ◽  
Light Curves ◽  
Secondary Component ◽  
High Mass ◽  
Dark Spot ◽  
Left Shoulder ◽  
Mass Ratio ◽  
Convective Envelope ◽  
Contact Binary

Abstract Multi-color light curves of CSS J075415.6+191052 and NW Leo are presented and the photometric solutions suggest that CSS J075415.6+191052 is a low mass ratio (q=0.178) and slightly deep contact binary (f=34.9%), while NW Leo with high mass ratio (q=0.707) and shallow degree of contact (f=2.3%). For CSS J075415.6+191052, the RI light curves show weakening around the left shoulder of secondary minimum, which indicates that there may be a dark spot on the secondary component. However, the light curves of BV bands are totally symmetric. It is unreasonable if the dark spot is caused by magnetic activity or mass transfers between two components. Therefore, the weakening of the light curves in this contact binary is caused by something else. A possible explanation is mass transferring from primary component to common convective envelope through the inner Lagrangian point, and this part of the mass, for some reason, weakens RI bands of light from secondary component. O - C analysis of NW Leo reveals a cyclic period change with a modulation period of 4.7 years, which may be caused by the light travel time effect of a third body. The positions of CSS J075415.6+191052 and NW Leo in P - J_{orb}' diagram suggest that the former is more evolved, which is in agreement with their photometric solutions. In the current stage, CSS J075415.6+191052 is dominated by the angular momentum loss theory, but NW Leo mainly follow the thermal relaxation oscillation theory.

The unusual, high-mass-ratio contact binary VZ PISCIUM

1989 ◽  
Vol 97 ◽  
pp. 532 ◽  
Author(s):  
Bruce J. Hrivnak ◽  
E. F. Milone
Keyword(s):  
High Mass ◽  
Mass Ratio ◽  
Contact Binary

scholarly journals The First Photometric Study of NSVS 1461538: A New W-subtype Contact Binary with a Low Mass Ratio and Moderate Fill-out Factor

2016 ◽  
Vol 33 (3) ◽  
pp. 185-196 ◽  
Author(s):  
Hyoun-Woo Kim ◽  
Chun-Hwey Kim ◽  
Mi-Hwa Song ◽  
Min-Ji Jeong ◽  
Hye-Young Kim
Keyword(s):  
Photometric Study ◽  
Mass Ratio ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio

The Numerical Simulation of Two-Degrees-of-Freedom Vortex-Induced Vibrations of Circular Cylinder with High Mass-Ratio

2013 ◽  
Vol 284-287 ◽  
pp. 557-561
Author(s):  
Jie Li Fan ◽  
Wei Ping Huang
Keyword(s):  
Circular Cylinder ◽  
Drag Force ◽  
Frequency Ratio ◽  
Lift Force ◽  
Degrees Of Freedom ◽  
Cross Flow ◽  
High Mass ◽  
Mass Ratio ◽  
Main Frequency ◽  
Line Amplitude

The two-degrees-of-freedom VIV of the circular cylinder with high mass-ratio is numerically simulated with the software ANSYS/CFX. The VIV characteristic is analyzed in the different conditions (Ur=3, 5, 6, 8, 10). When Ur is 5, 6, 8 and 10, the conclusion which is different from the cylinder with low mass-ratio can be obtained. When Ur is 3, the frequency of in-line VIV is twice of that of cross-flow VIV which is equal to the frequency ratio between drag force and lift force, and the in-line amplitude is much smaller than the cross-flow amplitude. The motion trace is the crescent. When Ur is 5 and 6, the frequency ratio between the drag force and lift force is still 2, but the main frequency of in-line VIV is mainly the same as that of cross-flow VIV and the secondary frequency of in-line VIV is equal to the frequency of the drag force. The in-line amplitude is still very small compared with the cross-flow amplitude. When Ur is up to 8 and 10, the frequency of in-line VIV is the same as the main frequency of cross-flow VIV which is close to the inherent frequency of the cylinder and is different from the frequency of drag force or lift force. But the secondary frequency of cross-flow VIV is equal to the frequency of the lift force. The amplitude ratio of the VIV between in-line and cross-flow direction is about 0.5. When Ur is 5, 6, 8 and 10, the motion trace is mainly the oval.

scholarly journals NEW CCD OBSERVATIONS AND THE FIRST PHOTOMETRIC STUDY OF THE CONTACT BINARY AP UMI

2016 ◽  
Vol 49 (3) ◽  
pp. 65-71
Author(s):  
N.S. AWADALLA ◽  
M.A. HANNA ◽  
M.N. ISMAIL ◽  
I.A. HASSAN ◽  
M.A. ELKHAMISY
Keyword(s):  
Photometric Study ◽  
Ccd Observations ◽  
Contact Binary

scholarly journals Two Contact Binaries with Mass Ratios Close to the Minimum Mass Ratio

2021 ◽  
Vol 922 (2) ◽  
pp. 122
Author(s):  
Kai Li ◽  
Qi-Qi Xia ◽  
Chun-Hwey Kim ◽  
Shao-Ming Hu ◽  
Di-Fu Guo ◽  
...  
Keyword(s):  
Gyration Radius ◽  
Mass Ratio ◽  
Mass Ratios ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Ratio Limit ◽  
Low Mass Ratio ◽  
Diagram Analysis

Abstract The cutoff mass ratio is under debate for contact binaries. In this paper, we present the investigation of two contact binaries with mass ratios close to the low mass ratio limit. It is found that the mass ratios of VSX J082700.8+462850 (hereafter J082700) and 1SWASP J132829.37+555246.1 (hereafter J132829) are both less than 0.1 (q ∼ 0.055 for J082700 and q ∼ 0.089 for J132829). J082700 is a shallow contact binary with a contact degree of ∼19%, and J132829 is a deep contact system with a fill-out factor of ∼70%. The O − C diagram analysis indicated that the two systems manifested long-term period decreases. In addition, J082700 exhibits a cyclic modulation which is more likely resulting from the Applegate mechanism. In order to explore the properties of extremely low mass ratio contact binaries (ELMRCBs), we carried out a statistical analysis on contact binaries with mass ratios of q ≲ 0.1 and discovered that the values of J spin/J orb of three systems are greater than 1/3. Two possible explanations can interpret this phenomenon. One explanation is that some physical processes, unknown to date, are not considered when Hut presented the dynamic stability criterion. The other explanation is that the dimensionless gyration radius (k) should be smaller than the value we used (k 2 = 0.06). We also found that the formation of ELMRCBs possibly has two channels. The study of evolutionary states of ELMRCBs reveals that their evolutionary states are similar with those of normal W UMa contact binaries.

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