scholarly journals Observing Program Calculator for Eclipsing Binary Star Systems

2012 ◽  
Vol 11 (1 and 2) ◽  
Author(s):  
Colby Neal ◽  
Michael Braunstein
Keyword(s):  
Local Time ◽  
Binary Stars ◽  
Binary Systems ◽  
Extrasolar Planets ◽  
Binary Star ◽  
Stellar System ◽  
Sidereal Time ◽  
Eclipsing Binary ◽  
Use Of Resources ◽  
Julian Date

A Microsoft Excel application has been developed to utilize eclipsing binary elements to calculate binary ephemerides that are useful in a program of observing binary systems. Binary star systems consist of two stars orbiting a common center of mass. Consistent monitoring of eclipsing binary stars is important for establishing fundamental astronomical parameters, such as mass and composition of the stellar system. The application that was developed supports effective use of resources in such monitoring applications. The main quantities computed by the application at the time of the eclipse include: local time, Julian date, starting Epoch, altitude of the system, phase of the moon, Local Mean Sidereal Time, and Local Hour Angle. Other quantities computed by the application include current Universal Time (UT), UT/Local Time correction, Julian Date, and current moon phase/percent illuminated. The observing application has been demonstrated to be effective in practical application to obtain differential photometry data for SV Camelopardalis, a system of interest because of variability in its period caused by a third body. The application can be easily modified for use with other highly periodic astronomical systems, for instance transits of extrasolar planets.

scholarly journals Discovery and characterisation of long-period eclipsing binary stars from Kepler K2 campaigns 1, 2, and 3

2018 ◽  
Vol 616 ◽  
pp. A38 ◽  
Author(s):  
P. F. L. Maxted ◽  
R. J. Hutcheon
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Eclipsing Binaries ◽  
Star Model ◽  
Eclipsing Binary ◽  
Giant Stars ◽  
Long Period ◽  
Eclipsing Binary Stars

Context. The Kepler K2 mission now makes it possible to find and study a wider variety of eclipsing binary stars than has been possible to-date, particularly long-period systems with narrow eclipses. Aims. Our aim is to characterise eclipsing binary stars observed by the Kepler K2 mission with orbital periods longer than P ≈ 5.5 days. Methods. The ellc binary star model has been used to determine the geometry of eclipsing binary systems in Kepler K2 campaigns 1, 2 and 3. The nature of the stars in each binary is estimated by comparison to stellar evolution tracks in the effective temperature – mean stellar density plane. Results. 43 eclipsing binary systems have been identified and 40 of these are characterised in some detail. The majority of these systems are found to be late-type dwarf and sub-giant stars with masses in the range 0.6–1.4 solar masses. We identify two eclipsing binaries containing red giant stars, including one bright system with total eclipses that is ideal for detailed follow-up observations. The bright B3V-type star HD 142883 is found to be an eclipsing binary in a triple star system. We observe a series of frequencies at large multiples of the orbital frequency in BW Aqr that we tentatively identify as tidally induced pulsations in this well-studied eccentric binary system. We find that the faint eclipsing binary EPIC 201160323 shows rapid apsidal motion. Rotational modulation signals are observed in 13 eclipsing systems, the majority of which are found to rotate non-synchronously with their orbits. Conclusions. The K2 mission is a rich source of data that can be used to find long period eclipsing binary stars. These data combined with follow-up observations can be used to precisely measure the masses and radii of stars for which such fundamental data are currently lacking, e.g., sub-giant stars and slowly-rotating low-mass stars.

scholarly journals Circumbinary Planets and the SOLARIS Project

2011 ◽  
Vol 7 (S282) ◽  
pp. 111-116 ◽  
Author(s):  
Maciej Konacki ◽  
Piotr Sybilski ◽  
Stanisław K. Kozłowski ◽  
Milena Ratajczak ◽  
Krzysztof G. Hełminiak
Keyword(s):  
South America ◽  
Binary Stars ◽  
Extrasolar Planets ◽  
Binary Star ◽  
Multiple Star ◽  
Eclipsing Binary ◽  
Stellar Astronomy ◽  
Eclipsing Binary Stars ◽  
Spectroscopic Binary ◽  
Circumbinary Planets

AbstractExtrasolar planets in binary and multiple star systems have become a noticeable niche with about 50 planets among over 500 known. Here we however focus on a particular subset of exoplanets in binary star systems — circumbinary planets. They have the unique advantage that a search for circumbinary planets does also significantly contribute to the understanding of their parent stars. We review what is currently known about circumbinary planets and then introduce our two projects aimed at detecting circumbinary planets: The TATOOINE project to find circumbinary planets around non-eclipsing double-lined spectroscopic binary stars with precision radial velocities, and the SOLARIS project to detect circumbinary planets with the timing of eclipses of eclipsing binary stars. For the SOLARIS project, we were granted 2.6 million USD to establish a network of at least four robotic 0.5-m telescopes on three continents (Australia, Africa and South America) to carry out precision photometry of a sample of eclipsing binary stars. We expect that both projects will have a large impact also on the observational stellar astronomy.

scholarly journals ASAS census of twins

2020 ◽  
Vol 496 (3) ◽  
pp. 2605-2612
Author(s):  
Volkan Bakış ◽  
Zeki Eker ◽  
Oğuzhan Sarı ◽  
Gökhan Yücel ◽  
Eda Sonbaş
Keyword(s):  
Spectral Type ◽  
Binary Stars ◽  
Binary Systems ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
Eclipsing Binary ◽  
Type Distribution ◽  
Eclipsing Binary Stars ◽  
Detached Binaries

ABSTRACT Twin binaries were identified among the eclipsing binaries with δ > –30° listed in the All Sky Automated Survey (ASAS) catalogue. In addition to the known twin binaries in the literature, 68 new systems have been identified and photometric and spectroscopic observations were done. Colour, spectral type, temperature, ratio of radii and masses of the components have been derived and are presented. Including 12 twin binary systems that exist in both ASAS and the catalogue of absolute parameters of detached eclipsing binary stars, a total of 80 twin detached binary systems have been statistically studied. A comparison of the spectral type distribution of the twins with those of detached eclipsing binary stars in the ASAS database shows that the spectral type distribution of twins is similar to that of detached systems. This result has been interpreted as indicating that there is no special formation mechanism for twins compared to normal detached binaries. As a result of our case study for HD 154010, a twin binary, we present the precise physical parameters of the system.

scholarly journals Origin of the orbital period change in contact binary stars

2019 ◽  
Vol 28 (06) ◽  
pp. 1950044 ◽  
Author(s):  
V. V. Sargsyan ◽  
H. Lenske ◽  
G. G. Adamian ◽  
N. V. Antonenko
Keyword(s):  
Orbital Period ◽  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Period Change ◽  
Mass Asymmetry ◽  
Contact Binary Stars ◽  
Contact Binary ◽  
Energy Formula ◽  
Orbital Periods

The evolution of contact binary star systems in mass asymmetry (transfer) coordinate is considered. The orbital period changes are explained by an evolution in mass asymmetry towards the symmetry (symmetrization of binary system). It is predicted that decreasing and increasing orbital periods are related, respectively, with the nonoverlapping and overlapping stage of the binary star during its symmetrization. A huge amount of energy [Formula: see text][Formula: see text]J is converted from the potential energy into internal energy of the stars during the symmetrization. As shown, the merger of stars in the binary systems, including KIC 9832227, is energetically an unfavorable process. The sensitivity of the calculated results to the values of total mass and orbital angular momentum is analyzed.

scholarly journals Stability of planetary, single M dwarf, and binary star companions to Kepler detached eclipsing binaries and a possible five-body system

2020 ◽  
Vol 498 (3) ◽  
pp. 4356-4364
Author(s):  
A K Getley ◽  
B Carter ◽  
R King ◽  
S O’Toole
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Eclipsing Binaries ◽  
Body System ◽  
Star System ◽  
Flip Flop ◽  
Eclipsing Binary ◽  
Photometric Monitoring ◽  
Eclipsing Binary Star ◽  
M Dwarf

ABSTRACT In this study, we identify 11 Kepler systems (KIC 5255552, 5653126, 5731312, 7670617, 7821010, 8023317, 10268809, 10296163, 11519226, 11558882, and 12356914) with a flip-flop effect in the eclipse timing variations O − C diagrams of the systems, report on what these systems have in common and whether these systems are dynamically stable. These systems have previously reported high eccentric binary stars with highly eccentric third bodies/outer companions. We find that all of the additional bodies in the system are dynamically stable for the configurations previously reported and are therefore likely to exist as described. We also provide additional evidence of KIC 5255552 being a quadruple star system composed of an eclipsing binary pair and non-eclipsing binary pair with the possibility of a fifth body in the system. With the advent of the NASA’s Transiting Exoplanet Survey Satellite (TESS) exoplanet survey, its precision photometric monitoring offers an opportunity to help confirm more local eclipsing binary star companions, including planets.

scholarly journals Mass Ratio and Spot Parameter Estimation from Eclipsing Binary Star Light Curves

Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Dirk Terrell
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Computer Code ◽  
Light Curves ◽  
Physical Models ◽  
Stellar Structure ◽  
Valuable Insight ◽  
Eclipsing Binary ◽  
Apply Physical ◽  
Eclipsing Binary Star

Eclipsing binary stars have a rich history of contributing to the field of stellar astrophysics. Most of the available information on the fundamental properties of stars has come from the analysis of observations of binaries. The availability of powerful computers and sophisticated codes that apply physical models has resulted in determinations of masses and radii of sufficient accuracy to provide critical tests of theories of stellar structure and evolution. Despite their sophistication, these codes still require the guiding hand of trained scientists to extract reliable information. The computer code will produce results, but it is still imperative for the analyst to ensure that those results make astrophysical sense, and to ascertain their reliability. Care must be taken to ensure that we are asking the codes for parameters for which there is information in the data. The analysis of synthetic observations with simulated observational errors of typical size can provide valuable insight to the analysis process because the parameters used to generate the observations are known. Such observations are herein analyzed to guide the process of determining mass ratios and spot parameters from eclipsing binary light curves. The goal of this paper is to illustrate some of the subtleties that need to be recognized and treated properly when analyzing binary star data.

scholarly journals A New Binary Star System of EW Type in Draco: GSC 03905-01870

2018 ◽  
Author(s):  
Salvador Barquin
Keyword(s):  
Light Curve ◽  
Binary Stars ◽  
Variable Star ◽  
Binary Star ◽  
Type I ◽  
Star System ◽  
Primary Minimum ◽  
Eclipsing Binary ◽  
Eclipsing Binary Stars ◽  
Binary Star System

Discovery of a new binary star system (GSC 03905-01870 = USNO-B1.0 1431-0327922 = UCAC4 716-059522) in the Draco constellation is presented. It was discovered during a search for previously unreported eclipsing binary stars through the ASAS-SN database. The shape of the light curve and its characteristics (period of 0.428988±0.000001 d, amplitude of 0.34±0.02 V Mag, primary minimum epoch HJD 2457994.2756±0.0002) indicates that the new variable star is an eclipsing binary of W Ursae Majoris type. I registered this variable star in The International Variable Star Index (VSX), its AAVSO UID is 000-BMP-891.

scholarly journals Asteroseismology of Close Binary Stars: Tides and Mass Transfer

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhao Guo
Keyword(s):  
Mass Transfer ◽  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Close Binary ◽  
Close Binaries ◽  
Linear Mode ◽  
Stellar Oscillations ◽  
Theoretical Approaches ◽  
Stellar Interiors

The study of stellar oscillations allows us to infer the properties of stellar interiors. Meanwhile, fundamental parameters such as mass and radius can be obtained by studying stars in binary systems. The synergy between binarity and asteroseismology can constrain the parameter space of stellar properties and facilitate the asteroseismic inference. On the other hand, binarity also introduces additional complexities such tides and mass transfer. From an observational perspective, we briefly review the recent advances in the study of tidal effects on stellar oscillations, focusing on upper main sequence stars (F-, A-, or OB- type). The effect can be roughly divided into two categories. The first one concerns the tidally excited oscillations (TEOs) in eccentric binaries where TEOs are mostly due to resonances between dynamical tides and gravity modes of the star. TEOs appear as orbital-harmonic oscillations on top of the eccentric ellipsoidal light curve variations (the “heartbeat” feature). The second category is regarding the self-excited oscillations perturbed by static tides in circularized and synchronized close binaries. It includes the tidal deformation of the propagation cavity and its effect on eigenfrequencies, eigenfunctions, and the pulsation alignment. We list binary systems that show these two types of tidal effect and summarize the orbital and pulsation observables. We also discuss the theoretical approaches used to model these tidal oscillations and relevant complications such as non-linear mode coupling and resonance locking. Further information can be extracted from the observations of these oscillations which will improve our understanding of tides. We also discuss the effect of mass transfer, the extreme result of tides, on stellar oscillations. We bring to the readers' attention: (1) oscillating stars undergoing mass accretion (A-, F-, and OB type pulsators and white dwarfs), for which the pulsation properties may be changed significantly by accretion; (2) post-mass transfer pulsators, which have undergone a stable or unstable Roche-Lobe overflow. These pulsators have great potential in probing detailed physical processes in stellar interiors and mass transfer, as well as in studying the binary star populations.

scholarly journals Commission 26: Double and Multiple Stars (Etoiles Doubles Et Multiples)

2000 ◽  
Vol 24 (1) ◽  
pp. 186-189
Author(s):  
H. Zinnecker ◽  
C. Scarfe ◽  
C. Allen ◽  
T. Armstrong ◽  
W. Hartkopf ◽  
...  
Keyword(s):  
San Francisco ◽  
Large Scale ◽  
Binary Systems ◽  
Extrasolar Planets ◽  
Binary Star ◽  
The Sun ◽  
Double And Multiple Stars ◽  
Nearby Stars ◽  
Solar Type ◽  
Low Mass

This triennial report (1996-1999) reviews the subject from a somewhat personal angle, mostly related to binary star formation and young binary star populations – a subject whose time had come in the early 1990s and is now in full swing.Many astronomers have searched for binary systems among main-sequence stars, and two large-scale surveys published in 1991 and 1992 have already become classics. Well before they became famous for finding extrasolar planets (see below), observing teams led by Michel Mayor (Geneva Observatory) and Geoffrey Marcy (San Francisco State Univ., now Univ. of Calif, at Berkeley) spent many years searching for low-mass stellar companions of nearby stars. The late Antoine Duquennoy and Mayor surveyed all solar-type dwarfs (spectral types F7 through G9) within 20 pc of the Sun, while Debra Fischer and Marcy studied stars with somewhat lower mass (M dwarfs) slightly nearer to the Sun.

scholarly journals Polarimetry of Binary Stars and Exoplanets

2011 ◽  
Vol 7 (S282) ◽  
pp. 173-180
Author(s):  
Karen S. Bjorkman
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Orbital Inclination ◽  
Orbital Parameters ◽  
Circumstellar Environments ◽  
Exoplanet Systems

AbstractPolarimetry is a useful diagnostic of asymmetries in both circumstellar environments and binary star systems. Its sensitivity to asymmetries in systems means that it can help to uncover details about system orbital parameters, including providing information about the orbital inclination. Polarimetry can probe the circumstellar and/or circumbinary material as well. A number of significant results on binary systems have been produced by polarimetric studies. One might therefore expect that polarimetry could similarly play a useful role in studies of exoplanets, and a number of possible diagnostics for exoplanets have been proposed. However, the application of polarimetry to exoplanet research is only in preliminary stages, and the difficulties with applying the technique to exoplanets are non-trivial. This review will discuss the successes of polarimetry in analyzing binary systems, and consider the possibilities and challenges for extending similar analysis to exoplanet systems.

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