scholarly journals Detection of Contact Binaries Using Sparse High Phase Angle Light Curves

2007 ◽  
Vol 672 (1) ◽  
pp. L57-L60 ◽  
Author(s):  
Pedro Lacerda
Keyword(s):  
Phase Angle ◽  
Light Curves ◽  
Contact Binaries ◽  
High Phase

scholarly journals A statistical review of light curves and the prevalence of contact binaries in the Kuiper Belt

Icarus ◽  
2021 ◽  
Vol 356 ◽  
pp. 114098
Author(s):  
Mark R. Showalter ◽  
Susan D. Benecchi ◽  
Marc W. Buie ◽  
William M. Grundy ◽  
James T. Keane ◽  
...  
Keyword(s):  
Kuiper Belt ◽  
Light Curves ◽  
Statistical Review ◽  
Contact Binaries

scholarly journals SuperWASP variable stars: classifying light curves using citizen science

2021 ◽  
Vol 502 (1) ◽  
pp. 1299-1311
Author(s):  
Heidi B Thiemann ◽  
Andrew J Norton ◽  
Hugh J Dickinson ◽  
Adam McMaster ◽  
Ulrich C Kolb
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Data Set ◽  
Resultant Data ◽  
Sky Survey ◽  
Short Period ◽  
Contact Binaries ◽  
Analysis Of Results

ABSTRACT We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains >1 million classifications corresponding to >500 000 object–period combinations, provided by citizen–scientist volunteers. Volunteer-classified light curves have ∼89 per cent accuracy for detached and semidetached eclipsing binaries, but only ∼9 per cent accuracy for rotationally modulated variables, based on known objects. We demonstrate that this Zooniverse project will be valuable for both population studies of individual variable types and the identification of stellar variables for follow-up. We present preliminary findings on various unique and extreme variables in this analysis, including long-period contact binaries and binaries near the short-period cut-off, and we identify 301 previously unknown binaries and pulsators. We are now in the process of developing a web portal to enable other researchers to access the outputs of the SuperWASP variable stars project.

High-phase-angle observations of Neptune at 2650 and 7500 Å: Haze structure and particle properties

Icarus ◽  
1992 ◽  
Vol 99 (2) ◽  
pp. 302-317 ◽  
Author(s):  
Wayne R. Pryor ◽  
Robert A. West ◽  
Karen E. Simmons ◽  
Mona Delitsky
Keyword(s):  
Phase Angle ◽  
Particle Properties ◽  
High Phase

scholarly journals Contact binaries of spectral type O

1979 ◽  
Vol 83 ◽  
pp. 265-269 ◽  
Author(s):  
Kam-Ching Leung ◽  
Donald P. Schneider
Keyword(s):  
Direct Measurement ◽  
Spectral Type ◽  
Time Scale ◽  
Massive Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Consistent Model ◽  
Contact Binaries ◽  
Primary Attraction ◽  
V729 Cyg

The eclipsing binaries UW CMa, AO Cas, and V729 Cyg have been systems of great interest for over fifty years. The light curves are complex and suffer significant changes on a time scale of months, but the primary attraction of these systems is that both components have O-type spectra; thus they present us with some of the few possibilities for direct measurement of absolute dimensions of very massive stars. Much effort has been expended on these systems, but no really consistent model has emerged.

A high-mass-ratio red-dwarf contact binary with an extremely cool close-in red dwarf

2019 ◽  
Author(s):  
Xiao-Hui Fang ◽  
Shengbang Qian ◽  
Miloslav Zejda ◽  
Soonthornthum Boonrucksar ◽  
Xiao Zhou ◽  
...  
Keyword(s):  
Orbital Period ◽  
Light Curves ◽  
High Mass ◽  
Mass Ratio ◽  
Third Body ◽  
Dynamical Interaction ◽  
The Third ◽  
Short Period ◽  
Contact Binaries ◽  
Mass Component

Abstract 1SWASP J161335.80$-$284722.2 (hereafter J161335) is an eclipsing red-dwarf binary with an orbital period of $0.229778\:$d, which is around the short-period limit for contact binaries. Three sets of multi-color light curves of J161335 were obtained from different telescopes in 2015 and 2016 and are analyzed using the Wilson–Devinney method. We discovered that the system is a W-type contact system with a contact degree of 19% and a high mass ratio of 0.91. By using all available eclipse times, we found that the observed $-$ calculated $(O-C)$ diagram displays a cyclic oscillation with an amplitude of 0.00196($\pm 0.00006)\:$d and a period of 4.79($\pm 0.14)\:$yr while it undergoes a downward parabolic change. This downward variation corresponds to a continuous decrease in the orbital period at a rate of $dP/dt = -4.26(\pm$0.01) $\times$ 10$^{-7}\:$d$\:$yr$^{-1}$. The small-amplitude oscillation is explained as the light travel-time effect from the gravitational influence of a third body with a lowest mass of $M _{3}$ = 0.15($\pm 0.01)M_{\,\odot }$. In solving the light curves, we found that the third light is increasing, with the wavelength suggesting that the third body may be a cool red dwarf. This is in agreement with the results obtained by analyzing the $O-C$ diagram. The tertiary red dwarf is orbiting the central red-dwarf binary at an orbital separation of 2.8($\pm 0.2$) au. These results suggest that the J161335 system may be formed through early dynamical interaction where the original low-mass component was replaced by a higher-mass third body and the lower-mass component was kicked out to a wider orbit. In this way, a hierarchical triple system similar to J161335 with a high-mass-ratio binary and a small close-in third body is formed.

scholarly journals An Analysis of Neptune's Stratospheric Haze Using High-Phase-Angle Voyager Images

Icarus ◽  
1995 ◽  
Vol 113 (2) ◽  
pp. 232-266 ◽  
Author(s):  
Julianne I. Moses ◽  
Kathy Rages ◽  
James B. Pollack
Keyword(s):  
Phase Angle ◽  
High Phase

scholarly journals FIRST PHOTOMETRIC INVESTIGATION OF TWO ECLIPSING BINARY SYSTEMS CRTS J213033.6+213159 AND 1SWASP J212454.61+203030.8

2020 ◽  
Vol 56 (2) ◽  
pp. 225-234
Author(s):  
M. Martignoni ◽  
C. Barani ◽  
F. Acerbi ◽  
R. Michel
Keyword(s):  
Binary Systems ◽  
General Pattern ◽  
Light Curves ◽  
Eclipsing Binary ◽  
Type K ◽  
Contact Binaries ◽  
Photometric Investigation ◽  
Orbital Periods ◽  
Period Limit ◽  
First Time

The multicolour CCD light curves of the eclipsing binary systems CRTS J213033.6+213159 and 1SWASP J212454.61+203030.8 are presented for the first time, the observations are analyzed using the latest version of the WilsonDevinney code. Both the systems are found to be W UMa contact binaries belonging two different subtypes. All the light curves show the inverse O'Connell effect. By using our 2 times of minimum light for both the systems and the 187 and 105 ToMs extract from the SWASP observations, respectively for CRTS J213033.6+213159 and for 1SWASP J212454.61+203030.8, the orbital periods are here revised. The spectral type K of the systems and their short orbital periods (< 0.3 days), suggests that they are near the shortest period limit. The absolute dimensions are estimated and, from statistical diagrams, it is found that both components of the systems follow the general pattern of the relative subtype of W Ursae Majoris systems.

scholarly journals MULTI-FILTER LIGHT CURVES OF 29 VERY SHORT PERIOD CANDIDATE CONTACT BINARIES

2016 ◽  
Vol 151 (6) ◽  
pp. 168 ◽  
Author(s):  
C. Koen ◽  
T. Koen ◽  
R. O. Gray
Keyword(s):  
Light Curves ◽  
Short Period ◽  
Contact Binaries

scholarly journals Test of the Optimization Techniques for the Photometric Analysis of Contact Binaries

1992 ◽  
Vol 151 ◽  
pp. 387-390
Author(s):  
E. Lapasset ◽  
M. Gomez ◽  
R. Fariñas
Keyword(s):  
Optimization Techniques ◽  
Light Curves ◽  
Mass Ratio ◽  
Velocity Data ◽  
Photometric Analysis ◽  
Reliable Parameter ◽  
Contact Binaries ◽  
Cross Correlations ◽  
Grid Technique ◽  
Radial Velocity Data

We present light curve analyses of contact binaries and comparisons with previously published cross-correlations radial velocity data. The critical parameter q (mass-ratio) obtained from a grid technique is confronted with the spectroscopic value. For total eclipsing systems, both values are always in a good or reasonable agreement, including some stars with shallow light curves. For partial eclipsing systems, convergent photometric and spectroscopic results are obtained for an important set of stars. Two exceptions are V523 Cas and XY Boo for which some arguments are suggested. We concluded that reliable parameter determinations can be obtained from pure photometric solutions, by means of grid techniques.

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