Fourier analysis of the light curves of eclipsing binaries in the case of transit eclipses, with application to the eclipsing system YZ Cassiopeiae

1978 ◽  
Vol 57 (1) ◽  
pp. 71-98 ◽  
Author(s):  
M. Kuruta�
Keyword(s):  
Fourier Analysis ◽  
Eclipsing Binaries ◽  
Light Curves

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.

scholarly journals Studying bright variable stars with the Multi-site All-Sky CAmeRA (MASCARA)

2018 ◽  
Vol 617 ◽  
pp. A32 ◽  
Author(s):  
O. Burggraaff ◽  
G. J. J. Talens ◽  
J. Spronck ◽  
A.-L. Lesage ◽  
R. Stuik ◽  
...  
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Previous Record ◽  
La Palma ◽  
Powerful Means ◽  
New Variables ◽  
Candidate Variable ◽  
Order Variability

Context. The Multi-site All-Sky CAmeRA (MASCARA) aims to find the brightest transiting planet systems by monitoring the full sky at magnitudes 4 < V < 8.4, taking data every 6.4 s. The northern station has been operational on La Palma since February 2015. These data can also be used for other scientific purposes, such as the study of variable stars. Aims. In this paper we aim to assess the value of MASCARA data for studying variable stars by determining to what extent known variable stars can be recovered and characterised, and how well new, unknown variables can be discovered. Methods. We used the first 14 months of MASCARA data, consisting of the light curves of 53 401 stars with up to one million flux points per object. All stars were cross-matched with the VSX catalogue to identify known variables. The MASCARA light curves were searched for periodic flux variability using generalised Lomb–Scargle periodograms. If significant variability of a known variable was detected, the found period and amplitude were compared with those listed in the VSX database. If no previous record of variability was found, the data were phase folded to attempt a classification. Results. Of the 1919 known variable stars in the MASCARA sample with periods 0.1 < P < 10 days, amplitudes >2%, and that have more than 80 h of data, 93.5% are recovered. In addition, the periods of 210 stars without a previous VSX record were determined, and 282 candidate variable stars were newly identified. We also investigated whether second order variability effects could be identified. The O’Connell effect is seen in seven eclipsing binaries, of which two have no previous record of this effect. Conclusions. MASCARA data are very well suited to study known variable stars. They also serve as a powerful means to find new variables among the brightest stars in the sky. Follow-up is required to ensure that the observed variability does not originate from faint background objects.

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.

scholarly journals On the Application of Fourier Decomposition Parameters

1993 ◽  
Vol 134 ◽  
pp. 157-158
Author(s):  
J. O. Petersen
Keyword(s):  
Fourier Analysis ◽  
Light Curves ◽  
Amplitude Ratios ◽  
Fourier Decomposition ◽  
Practical Applications ◽  
Convincing Argument ◽  
Lee Form ◽  
Modern Form ◽  
Made In ◽  
Phase Differences

The application of Fourier decomposition parameters has revolutionized important areas of investigations of Cepheid type variables since the introduction of Fourier analysis in its modern form by Simon and Lee (1981).In the literature several different representations of the results of Fourier analysis have been utilized. In view of the growing interest for applications of Fourier decomposition it is important to use and publish Fourier data in an optimal way. Most studies until now have used amplitude ratios and phase differences derived from traditional light curves giving the light variation in magnitudes, following the original recipe of Simon and Lee (1981). However, Stellingwerf and Donohoe (1986) advocated the use of phases rather than phase differences. Recently, Buchler et al. (1990) argued that the standard Simon & Lee form contains all relevant physics, and suggested analysis of flux-values rather than of magnitudes, because this removes the distorting effects of constant, false light. Thus there are many choices to be made in practical applications of Fourier analysis, and there is at present no convincing argument for preferring one specific representation.

scholarly journals A Comparison Between Binary Star Light Curves and Those of Possible Binary Asteroids

1984 ◽  
Vol 80 ◽  
pp. 387-392
Author(s):  
H. J. Schober
Keyword(s):  
Light Curve ◽  
Binary Star ◽  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Binary Asteroids ◽  
Binary Nature ◽  
Rotation Rates ◽  
Photoelectric Observations

AbstractSince about ten years coordinated programs of photoelectric observations of asteroids are carried out to derive rotation rates and light curves. Quite a number of those asteroids exhibit features in their light curves, with similar characteristics as variable stars and especially eclipsing binaries. This would allow also an interpretation that there might be an evidence for the binary nature of some asteroids, based on observational hints. A few examples are given and a list of indications for the possible binary nature of asteroids, based on their light curve features, is presented.

scholarly journals Photometric and Radial Velocity Variations of R CrB Near Maximum Light

1985 ◽  
Vol 87 ◽  
pp. 191-197
Author(s):  
A.V. Raveendran ◽  
B.N. Ashoka ◽  
N. Kameswara Rao
Keyword(s):  
Fourier Analysis ◽  
Radial Velocity ◽  
Radial Velocities ◽  
Light Curves ◽  
Circumstellar Dust ◽  
Maximum Light ◽  
V Band ◽  
L Band ◽  
Velocity Variations ◽  
Visual Light

Abstract:Fourier analysis of the light curves of RCrB in V band near maximum shows that in addition to several significant short periods there is a modulation of the visual light with a period around 1170 day, similar to that of L band flux, noticed by strecker. This indicates that there is some contribution to the visual light variations of the star from the pulsating circumstellar dust. Radial velocities of R CrB obtained at Kavalur during February-May 1985 show variations with a period around 47 days.

scholarly journals Imaging stellar coronae from eclipsing binary X-ray light curves

1996 ◽  
Vol 176 ◽  
pp. 469-476 ◽  
Author(s):  
M. Siarkowski
Keyword(s):  
Eclipsing Binaries ◽  
Light Curves ◽  
Late Type ◽  
X Ray ◽  
Spatially Resolved ◽  
Direct Observations ◽  
Tidal Forces ◽  
Orbital Modulation ◽  
Orbital Periods ◽  
Detached Binaries

The Sun is the only star whose X-ray emitting, strongly inhomogenous corona can be spatially resolved via direct observations. For other late type-stars it is known that coronae do exist, but the spatial distribution of their emission is largely unknown. However in the case of eclipsing binaries this spatial structure can be potentially deduced from the orbital modulation of the observed X-ray light curve. The best candidates for this kind of analysis are RS CVn binaries, the most active and luminous late-type X-ray coronal sources. These are detached binaries with periods typically between 0.5 and 20 days, in which one or both stars have evolved into subgiant or giant of spectral type G or K. For short orbital periods (< 14 days) the tidal forces lead to synchronization of the orbital and rotational periods, so these systems rotate rigidly.

scholarly journals A survey for high-mass eclipsing binaries

2019 ◽  
Vol 490 (4) ◽  
pp. 5147-5173
Author(s):  
F Pozo Nuñez ◽  
R Chini ◽  
A Barr Domínguez ◽  
Ch Fein ◽  
M Hackstein ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Light Curves ◽  
High Mass ◽  
System Component ◽  
Fundamental Parameters ◽  
Average Value ◽  
Short Period ◽  
Orbital Periods ◽  
Photometric Monitoring ◽  
Period System

ABSTRACT We report results from a search for Galactic high-mass eclipsing binaries. The photometric monitoring campaign was performed in Sloan r and i with the robotic twin refractor RoBoTT at the Universitätssternwarte Bochum in Chile and complemented by Johnson UBV data. Comparison with the SIMBAD data base reveals 260 variable high-mass stars. Based on well-sampled light curves, we discovered 35 new eclipsing high-mass systems and confirm the properties of six previously known systems. For all objects, we provide the first light curves and determine orbital periods through the Lafler–Kinman algorithm. Apart from GSC 08173-0018 and Pismis 24-13 ($P = 19.47\, d$ and $20.14\, d$) and the exceptional short-period system TYC 6561-1765-1 ($P = 0.71\, d$), all systems have orbital periods between 1 and 9 d. We model the light curves of 26 systems within the framework of the Roche geometry and calculate fundamental parameters for each system component. The Roche lobe analysis indicates that 14 systems have a detached geometry, while 12 systems have a semidetached geometry; seven of them are near-contact systems. The deduced mass ratios q = M2/M1 reach from 0.4 to 1.0 with an average value of 0.8. The similarity of masses suggests that these high-mass binaries were created during the star formation process rather than by tidal capture.

scholarly journals First CCD observations of Magellanic Cloud variable stars from the Mt John University Observatory, New Zealand

1991 ◽  
Vol 148 ◽  
pp. 381-381
Author(s):  
William Tobin ◽  
A. C. Gilmore ◽  
Alan Wadsworth ◽  
S.R.D. West
Keyword(s):  
New Zealand ◽  
Evaluation Process ◽  
Variable Stars ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Ccd Observations ◽  
Differential Photometry

Late in 1988 the Mt John University Observatory acquired a cryogenic CCD system from Photometrics Ltd (Tucson). The chip is a Thomson CSF TH7882 CDA comprising 384 × 576 pixels. As part of the evaluation process, we have begun two differential photometry programs of the Magellanic Clouds using the Mt John 0.6m Boller & Chivens telescope. On this telescope each CCD pixel corresponds to 0.6 arcsec. Mt John's southerly latitude (44°S) permits year-round observations of the Clouds.The first program concerns B, V and I photometry of five blue eclipsing binaries selected, on the basis of Gaposchkin's (1970, 1977) photographic light curves, to have roughly equal components with minimal interaction. HV 12634 has also been observed for comparison with the CCD light curves published by Jensen et al. (1988). Fig. 1 shows the B observations so far obtained for HV 1761, but the reduction is preliminary, being based on aperture-integrated magnitudes. The field is populous, and a final reduction will require use of a crowded-field reduction package such as ROMAFOT.

Sign in / Sign up

Export Citation Format

Share Document