scholarly journals Survival of planets around shrinking stellar binaries

2015 ◽  
Vol 112 (30) ◽  
pp. 9264-9269 ◽  
Author(s):  
Diego J. Muñoz ◽  
Dong Lai
Keyword(s):  
Binary Stars ◽  
Orbital Evolution ◽  
Eclipsing Binaries ◽  
Target List ◽  
Tidal Dissipation ◽  
Compact Binaries ◽  
Kepler Mission ◽  
Orbital Decay ◽  
Erratic Behavior ◽  
Circumbinary Planets

The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov–Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like.

scholarly journals The binary mass ratios of circumbinary planet hosts

2019 ◽  
Vol 488 (3) ◽  
pp. 3482-3491 ◽  
Author(s):  
David V Martin
Keyword(s):  
Eclipsing Binaries ◽  
Close Binary ◽  
Mass Ratio ◽  
Ratio Distribution ◽  
Kepler Mission ◽  
Binary Formation ◽  
Formation And Evolution ◽  
Observational Bias ◽  
First Time ◽  
Circumbinary Planets

Abstract Almost a dozen circumbinary planets have been found transiting eclipsing binaries. For the first time the observational bias of this sample is calculated with respect to the mass ratio of the host binaries. It is shown that the mass ratio affects transit detection in multiple, sometimes subtle ways, through stability and dynamics of orbits, dilution of transit depths, and the geometric transit and eclipse probabilities. Surprisingly though, it is found that these effects largely cancel out. Consequently, the transit detections in the Kepler mission are essentially unbiased with respect to mass ratio, and hence likely representative of the true underlying population. It is shown that the mass ratio distribution of circumbinary hosts may be the same as field binaries, and hence roughly uniform, but more observations are needed to deduce any subtle differences. These results are discussed in the context of close binary formation and evolution, of which the mass ratio is believed to be a marker, and other surveys for circumbinary planets including TESS and BEBOP.

scholarly journals TheKepler Missionand Eclipsing Binaries

2006 ◽  
Vol 2 (S240) ◽  
pp. 236-243 ◽  
Author(s):  
David Koch ◽  
William Borucki ◽  
Gibor Basri ◽  
Timothy Brown ◽  
Douglas Caldwell ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Light Curves ◽  
Field Of View ◽  
Habitable Zone ◽  
Target List ◽  
Kepler Mission ◽  
Photometric Observations ◽  
Single Field ◽  
Verification Process

AbstractTheKepler Missionis a space-based photometric mission with a differential photometric precision of 14 ppm (atV= 12 for a 6.5 hour transit). It is designed to continuously observe a single field of view (FOV) of greater then 100 square degrees in the Cygnus-Lyra region for four or more years. The primary goal of the mission is to monitor more than one-hundred thousand stars for transits of Earth-size and smaller planets in the habitable zone of solar-like stars. In the process, many eclipsing binaries (EB) will also be detected and light curves produced. To enhance and optimize the mission results, the stellar characteristics for all the stars in theKeplerFOV withV< 16 will have been determined prior to launch. As part of the verification process, stars with transit candidates will have radial-velocity follow-up observations performed to determine the component masses and thereby separate eclipses caused by stellar companions from transits caused by planets. The result will be a rich database on EBs. The community will have access to the archive for further analysis, such as, for EB modeling of the high-precision light curves. A guest observer program is also planned to allow for photometric observations of objects not on the target list but within the FOV.

scholarly journals Advances in Modeling Eclipsing Binary Stars in the Era of Large All-Sky Surveys with EBAI and PHOEBE

2011 ◽  
Vol 7 (S282) ◽  
pp. 271-278 ◽  
Author(s):  
A. Prša ◽  
E. F. Guinan ◽  
E. J. Devinney ◽  
P. Degroote ◽  
S. Bloemen ◽  
...  
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Lessons Learned ◽  
Eclipsing Binaries ◽  
Eclipsing Binary ◽  
Fundamental Properties ◽  
Eclipsing Binary Stars ◽  
Kepler Mission ◽  
Theoretical Predictions ◽  
Eclipsing Binary Star

AbstractWith the launch of NASA's Kepler mission, stellar astrophysics in general, and the eclipsing binary star field in particular, has witnessed a surge in data quality, interpretation possibilities, and the ability to confront theoretical predictions with observations. The unprecedented data accuracy and an essentially uninterrupted observing mode of over 2000 eclipsing binaries is revolutionizing the field. Amidst all this excitement, we came to realize that our best models to describe the physical and geometric properties of binaries are not good enough. Systematic errors are evident in a large range of binary light curves, and the residuals are anything but Gaussian. This is crucial because it limits us in the precision of the attained parameters. Since eclipsing binary stars are prime targets for determining the fundamental properties of stars, including their ages and distances, the penalty for this loss of accuracy affects other areas of astrophysics as well. Here, we propose to substantially revamp our current models by applying the lessons learned while reducing, modeling, and analyzing Kepler data.

scholarly journals Testing convection in stellar models using detached eclipsing binaries

2006 ◽  
Vol 2 (S239) ◽  
pp. 157-159
Author(s):  
John Southworth ◽  
Hans Bruntt
Keyword(s):  
Binary Stars ◽  
Eclipsing Binaries ◽  
Eclipsing Binary ◽  
Fundamental Properties ◽  
Eclipsing Binary Stars ◽  
Average System ◽  
Stellar Models

AbstractThe fundamental properties of detached eclipsing binary stars can be measured very accurately, which could make them important objects for constraining the treatment of convection in theoretical stellar models. However, only four or five pieces of information can be found for the average system, which is not enough. We discuss studies of more interesting and useful objects: eclipsing binaries in clusters and eclipsing binaries with pulsating components.

scholarly journals Tidal interactions in rotating multiple stars and their impact on their evolution

2014 ◽  
Vol 9 (S307) ◽  
pp. 208-210
Author(s):  
P. Auclair-Desrotour ◽  
S. Mathis ◽  
C. Le Poncin-Lafitte
Keyword(s):  
Fluid Model ◽  
Orbital Evolution ◽  
Tidal Dissipation ◽  
Tidal Waves ◽  
Physical Mechanisms ◽  
Tidal Interactions ◽  
The Earth ◽  
Half Height ◽  
Multiple Stars ◽  
Stellar Interiors

AbstractTidal dissipation in stars is one of the key physical mechanisms that drive the evolution of binary and multiple stars. As in the Earth oceans, it corresponds to the resonant excitation of their eigenmodes of oscillation and their damping. Therefore, it strongly depends on the internal structure, rotation, and dissipative mechanisms in each component. In this work, we present a local analytical modeling of tidal gravito-inertial waves excited in stellar convective and radiative regions respectively. This model allows us to understand in details the properties of the resonant tidal dissipation as a function of the excitation frequencies, the rotation, the stratification, and the viscous and thermal properties of the studied fluid regions. Then, the frequencies, height, width at half-height, and number of resonances as well as the non-resonant equilibrium tide are derived analytically in asymptotic regimes that are relevant in stellar interiors. Finally, we demonstrate how viscous dissipation of tidal waves leads to a strongly erratic orbital evolution in the case of a coplanar binary system. We characterize such a non-regular dynamics as a function of the height and width of resonances, which have been previously characterized thanks to our local fluid model.

scholarly journals Tidal dissipation in rotating low-mass stars and implications for the orbital evolution of close-in planets

2017 ◽  
Vol 604 ◽  
pp. A112 ◽  
Author(s):  
F. Gallet ◽  
E. Bolmont ◽  
S. Mathis ◽  
C. Charbonnel ◽  
L. Amard
Keyword(s):  
Orbital Evolution ◽  
Low Mass Stars ◽  
Tidal Dissipation ◽  
Low Mass

scholarly journals Tidal evolution of circumbinary systems with arbitrary eccentricities: applications for Kepler systems

2020 ◽  
Vol 634 ◽  
pp. A12
Author(s):  
F. A. Zoppetti ◽  
A. M. Leiva ◽  
C. Beaugé
Keyword(s):  
Time Lag ◽  
Semimajor Axis ◽  
Tidal Flow ◽  
Orbital Evolution ◽  
Axis Ratio ◽  
Tidal Evolution ◽  
Tidal Interactions ◽  
Orbital Instability ◽  
Outward Migration ◽  
Circumbinary Planets

We present an extended version of the Constant Time Lag analytical approach for the tidal evolution of circumbinary planets introduced in our previous work. The model is self-consistent, in the sense that all tidal interactions between pairs are computed, regardless of their size. We derive analytical expressions for the variational equations governing the spin and orbital evolution, which are expressed as high-order elliptical expansions in the semimajor axis ratio but retain closed form in terms of the binary and planetary eccentricities. These are found to reproduce the results of the numerical simulations with arbitrary eccentricities very well, as well as reducing to our previous results in the low-eccentric case. Our model is then applied to the well-characterised Kepler circumbinary systems by analysing the tidal timescales and unveiling the tidal flow around each different system. In all cases we find that the spins reach stationary values much faster than the characteristic timescale of the orbital evolution, indicating that all Kepler circumbinary planets are expected to be in a sub-synchronous state. On the other hand, all systems are located in a tidal flow leading to outward migration; thus the proximity of the planets to the orbital instability limit may have been even greater in the past. Additionally, Kepler systems may have suffered a significant tidally induced eccentricity damping, which may be related to their proximity to the capture eccentricity. To help understand the predictions of our model, we also offer a simple geometrical interpretation of our results.

scholarly journals Close-In Substellar Companions and the Formation of sdB-Type Close Binary Stars

2015 ◽  
Vol 2 (1) ◽  
pp. 183-187 ◽  
Author(s):  
L. Y. Zhu ◽  
S. B. Qian ◽  
E.-G. Zhao ◽  
E. Fernández Lajús ◽  
Z.-T. Han
Keyword(s):  
Binary Stars ◽  
Eclipsing Binaries ◽  
Close Binary ◽  
Close Binaries ◽  
Close Binary Stars ◽  
Cataclysmic Binaries ◽  
Low Mass ◽  
Substellar Companions ◽  
Orbital Periods

The sdB-type close binaries are believed to have experienced a common-envelope phase and may evolve into cataclysmic binaries (CVs). About 10% of all known sdB binaries are eclipsing binaries consisting of very hot subdwarf primaries and low-mass companions with short orbital periods. The eclipse profiles of these systems are very narrow and deep, which benefits the determination of high precise eclipsing times and makes the detection of small and close-in tertiary bodies possible. Since 2006 we have monitored some sdB-type eclipsing binaries to search for the close-in substellar companions by analyzing the light travel time effect. Here some progresses of the program are reviewed and the formation of sdB-type binary is discussed.

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 &gt; –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.

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