scholarly journals Photometric Analysis of Wide and Narrow Hα Band Observations of R Canis Majoris

1992 ◽  
Vol 151 ◽  
pp. 303-306
Author(s):  
M. Taghi Edalati ◽  
Timothy Banks ◽  
Edwin Budding
Keyword(s):  
Hot Spot ◽  
Optimal Estimate ◽  
Mass Ratio ◽  
Transfer Effects ◽  
Photometric Analysis ◽  
Index Variation ◽  
Algol System ◽  
Low Mass ◽  
Low Mass Ratio ◽  
Optimisation Technique

Wide and narrow Hα lightcurves of R CMa were analysed using Wilson-Devinney (WD) and Information Limit Optimisation Technique (ILOT) approaches. A range of mass ratios, tested by both methods, led to an optimal estimate of around 0.45, at variance with the spectroscopic value. The distortion on the light curve affects the modelling, and so, in a second fitting, this was represented by a ‘hot spot’, associated with mass transfer effects. A semi-detached configuration was then derived. This is supported by the form of the Hα index variation, which has also been modelled. Although thus appearing as a ‘classical Algol’ system, R CMa retains its inherent peculiarity of low mass ratio with low period, which cannot be reconciled with conservative evolution scenarios.

scholarly journals ZZ Piscis Austrinus (ZZ PsA): a bright red nova progenitor and the instability mass ratio of contact binary stars

2020 ◽  
Vol 501 (1) ◽  
pp. 229-235
Author(s):  
Surjit S Wadhwa ◽  
Ain De Horta ◽  
Miroslav D Filipović ◽  
N F H Tothill ◽  
Bojan Arbutina ◽  
...  
Keyword(s):  
Binary System ◽  
Binary Stars ◽  
Current Status ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Spectral Class ◽  
Contact Binary Stars ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio

ABSTRACT ZZ Piscis Austrinus (ZZ PsA) is a neglected bright southern contact binary system with maximum V magnitude of 9.26. We present the first multiband photometric analysis and find the system to be in deep contact (>95 per cent) with an extremely low mass ratio of 0.078. The primary has a mass of 1.213 M⊙ in keeping with its reported spectral class of F6. In order to determine if ZZ PsA is a merger candidate, we outline the current status regarding the instability mass ratio and develop new relationship linking the mass of the primary to the instability mass ratio of the system and the degree of contact. We find that ZZ PsA along with two other examples from the literature to be merger candidates while an additional three require further observations to be confirmed as potential merger candidates.

The first photometric analysis of two low mass ratio totally eclipsing contact binaries: TIC 393943031 and TIC 89428764

2021 ◽  
Author(s):  
Yanke Tang ◽  
Yani Guo ◽  
Kai Li ◽  
Ning Gai ◽  
Zhikai Li
Keyword(s):  
Mass Transfer ◽  
Primary Component ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Angular Momenta ◽  
Contact Binaries ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio ◽  
First Time

Abstract PhotometricanalysisofthecontactbinariesTIC393943031andTIC89428764was carried out usingTESS and SuperWASP data for the first time. Using Wilson-Devinneycode, we have discovered TIC 393943031 is a low-mass-ratio deep contact binary with a fillout factor of 50.9(±1)% and a mass ratio of q = 0.163 ± 0.001. TIC 89428764 is a medium and low-mass-ratio contact binary with a fillout factor of 34.5(±1)% and a mass ratio of q = 0.147±0.001. Furthermore, the period study reveals both the stars exhibit continuously increasing periods, the increasing rate is 4.21×10−7day ·year−1for TIC 393943031while 6.36 × 10−7day · year−1for TIC 89428764. The possible reason is mass transfer from the secondary component to the primary component for both the stars. Meanwhile, we discussed their evolutionary phases and orbital angular momenta.

scholarly journals Photometric analysis of three totally eclipsing W UMa stars with increasing periods: TYC 3700-1384-1, V1511 Her and V1179 Her

2020 ◽  
Author(s):  
Eric Broens
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
Primary Component ◽  
Evolutionary Status ◽  
Mass Ratio ◽  
Main Sequence Stars ◽  
Photometric Analysis ◽  
Transfer Rates ◽  
Low Mass ◽  
Low Mass Ratio

Abstract The first multi-colour light curve models and period studies for the totally eclipsing W UMa stars TYC 3700-1384-1, V1511 Her and V1179 Her are presented. All three stars are A-subtype W UMa stars of spectral type F. The light curve solutions show that TYC 3700-1384-1 has a moderately low mass ratio of q = 0.182 ± 0.001 and a degree of overcontact of $f = 49 \%$. For V1179 Her a mass ratio q = 0.153 ± 0.001 and a degree of overcontact of $f = 48 \%$ is derived. The solution for V1511 Her is inconclusive, however the mass ratio is expected to be between 0.13 < q < 0.15. The evolutionary status is compared with zero-age main sequence stars taking into account energy transfer from the primary to the secondary component. The primary component of TYC 3700-1384-1 fits well in the main-sequence, while V1179 Her is more evolved. The period study reveals for all three stars a continuously increasing period at a rate of dP/dt = 6.1 × 10−7dyr−1, dP/dt = 5.0 × 10−7dyr−1 and dP/dt = 9.6 × 10−7dyr−1 for TYC 3700-1384-1, V1511 Her and V1179 Her respectively. The estimated mass transfer rates derived from these period changes are $\dot{M}=1.6 \times 10^{-7} {\, {\rm M}_\odot } yr^{-1}$ for TYC 3700-1384-1 and $\dot{M}= 1.9 \times 10^{-7} {\, {\rm M}_\odot } yr^{-1}$ for V1179 Her.

scholarly journals Photometric analysis of two extreme low mass ratio contact binary systems

2021 ◽  
Vol 21 (9) ◽  
pp. 235
Author(s):  
Surjit S. Wadhwa ◽  
Nick F. H. Tothill ◽  
Ain Y. DeHorta ◽  
Miroslav Filipović
Keyword(s):  
Binary Systems ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Contact Binary ◽  
Low Mass ◽  
Low Mass Ratio

scholarly journals Marginally low mass ratio close binary system V1191 Cyg

New Astronomy ◽  
2012 ◽  
Vol 17 (1) ◽  
pp. 46-49 ◽  
Author(s):  
B. Ulaş ◽  
B. Kalomeni ◽  
V. Keskin ◽  
O. Köse ◽  
K. Yakut
Keyword(s):  
Binary System ◽  
Close Binary System ◽  
Close Binary ◽  
Mass Ratio ◽  
Low Mass ◽  
Low Mass Ratio

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.

Deep, Low Mass Ratio Overcontact Binary Systems. VI. AH Cancri in the Old Open Cluster M67

2006 ◽  
Vol 131 (6) ◽  
pp. 3028-3039 ◽  
Author(s):  
S.-B. Qian ◽  
L. Liu ◽  
B. Soonthornthum ◽  
L.-Y. Zhu ◽  
J.-J. He
Keyword(s):  
Binary Systems ◽  
Open Cluster ◽  
Mass Ratio ◽  
Low Mass ◽  
Low Mass Ratio
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