scholarly journals Habitable planet formation in extreme planetary systems: systems with multiple stars and/or multiple planets

2007 ◽  
Vol 3 (S249) ◽  
pp. 319-324
Author(s):  
Nader Haghighipour
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Planet Formation ◽  
Planetary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
Habitable Planets ◽  
Multiple Stars ◽  
Habitable Zones ◽  
Habitable Planet

AbstractUnderstanding the formation and dynamical evolution of habitable planets in extrasolar planetary systems is a challenging task. In this respect, systems with multiple giant planets and/or multiple stars present special complications. The formation of habitable planets in these environments is strongly affected by the dynamics of their giant planets and/or their stellar companions. These objects have profound effects on the structure of the disk of planetesimals and protoplanetary objects in which terrestrial-class planets are formed. To what extent the current theories of planet formation can be applied to such “extreme” planetary systems depends on the dynamical characteristics of their planets and/or their binary stars. In this paper, I present the results of a study of the possibility of the existence of Earth-like objects in systems with multiple giant planets (namely υ Andromedae, 47 UMa, GJ 876, and 55 Cnc) and discuss the dynamics of the newly discovered Neptune-sized object in 55 Cnc system. I will also review habitable planet formation in binary systems and present the results of a systematic search of the parameter-space for which Earth-like objects can form and maintain long-term stable orbits in the habitable zones of binary stars.

Formation, Frequency and Spacing of Habitable Planets

1997 ◽  
Vol 161 ◽  
pp. 289-297
Author(s):  
Jack J. Lissauer
Keyword(s):  
Planet Formation ◽  
Orbital Stability ◽  
Young Stars ◽  
Giant Planets ◽  
Terrestrial Planets ◽  
Habitable Zone ◽  
Habitable Planets ◽  
Habitable Zones ◽  
Planetary Orbits ◽  
Rocky Planets

AbstractModels of planet formation and of the orbital stability of planetary systems are described and used to discuss estimates of the abundance of habitable planets which may orbit stars within our galaxy. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that most single stars should have rocky planets in orbit about them. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets orbiting within or near the habitable zone could either prevent terrestrial planets from forming, destroy such planets or remove them from habitable zones. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

scholarly journals Earth-size planet formation in the habitable zone of circumbinary stars

2020 ◽  
Vol 494 (1) ◽  
pp. 1045-1057 ◽  
Author(s):  
G O Barbosa ◽  
O C Winter ◽  
A Amarante ◽  
A Izidoro ◽  
R C Domingos ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Planet Formation ◽  
Terrestrial Planet ◽  
Close Binary ◽  
Habitable Zone ◽  
Density Profiles ◽  
Habitable Planets ◽  
Habitable Zones ◽  
Test Particles ◽  
The Stability

ABSTRACT This work investigates the possibility of close binary (CB) star systems having Earth-size planets within their habitable zones (HZs). First, we selected all known CB systems with confirmed planets (totaling 22 systems) to calculate the boundaries of their respective HZs. However, only eight systems had all the data necessary for the computation of HZ. Then, we numerically explored the stability within HZs for each one of the eight systems using test particles. From the results, we selected five systems that have stable regions inside HZs, namely Kepler-34,35,38,413, and 453. For these five cases of systems with stable regions in HZ, we perform a series of numerical simulations for planet formation considering discs composed of planetary embryos and planetesimals, with two distinct density profiles, in addition to the stars and host planets of each system. We found that in the case of the Kepler-34 and 453 systems, no Earth-size planet is formed within HZs. Although planets with Earth-like masses were formed in Kepler-453, they were outside HZ. In contrast, for the Kepler-35 and 38 systems, the results showed that potentially habitable planets are formed in all simulations. In the case of the Kepler-413system, in just one simulation, a terrestrial planet was formed within HZ.

scholarly journals On the survival of resonant and non-resonant planetary systems in star clusters

2020 ◽  
Vol 497 (2) ◽  
pp. 1807-1825
Author(s):  
Katja Stock ◽  
Maxwell X Cai ◽  
Rainer Spurzem ◽  
M B N Kouwenhoven ◽  
Simon Portegies Zwart
Keyword(s):  
Solar System ◽  
Star Clusters ◽  
Planetary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
Mean Motion Resonances ◽  
Orbital Parameters ◽  
Eccentric Orbits ◽  
The Individual ◽  
Exoplanet Systems

ABSTRACT Despite the discovery of thousands of exoplanets in recent years, the number of known exoplanets in star clusters remains tiny. This may be a consequence of close stellar encounters perturbing the dynamical evolution of planetary systems in these clusters. Here, we present the results from direct N-body simulations of multiplanetary systems embedded in star clusters containing N = 8k, 16k, 32k, and 64k stars. The planetary systems, which consist of the four Solar system giant planets Jupiter, Saturn, Uranus, and Neptune, are initialized in different orbital configurations, to study the effect of the system architecture on the dynamical evolution of the entire planetary system, and on the escape rate of the individual planets. We find that the current orbital parameters of the Solar system giants (with initially circular orbits, as well as with present-day eccentricities) and a slightly more compact configuration, have a high resilience against stellar perturbations. A configuration with initial mean-motion resonances of 3:2, 3:2, and 5:4 between the planets, which is inspired by the Nice model, and for which the two outermost planets are usually ejected within the first 105 yr, is in many cases stabilized due to the removal of the resonances by external stellar perturbation and by the rapid ejection of at least one planet. Assigning all planets the same mass of 1 MJup almost equalizes the survival fractions. Our simulations reproduce the broad diversity amongst observed exoplanet systems. We find not only many very wide and/or eccentric orbits, but also a significant number of (stable) retrograde orbits.

scholarly journals Planets in Binaries: Formation and Dynamical Evolution

Galaxies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 84 ◽  
Author(s):  
Francesco Marzari ◽  
Philippe Thebault
Keyword(s):  
Binary Systems ◽  
Planet Formation ◽  
Dynamical Evolution ◽  
Type Systems ◽  
Hyperbolic Orbit ◽  
Companion Star ◽  
Mean Motion Resonances ◽  
Disk Formation ◽  
P Type ◽  
Two Populations

Binary systems are very common among field stars, yet the vast majority of known exoplanets have been detected around single stars. While this relatively small number of planets in binaries is probably partly due to strong observational biases, there is, however, statistical evidence that planets are indeed less frequent in binaries with separations smaller than 100 au, strongly suggesting that the presence of a close-in companion star has an adverse effect on planet formation. It is indeed possible for the gravitational pull of the second star to affect all the different stages of planet formation, from proto-planetary disk formation to dust accumulation into planetesimals, to the accretion of these planetesimals into large planetary embryos and, eventually, the final growth of these embryos into planets. For the crucial planetesimal-accretion phase, the complex coupling between dynamical perturbations from the binary and friction due to gas in the proto-planetary disk suggests that planetesimal accretion might be hampered due to increased, accretion-hostile impact velocities. Likewise, the interplay between the binary’s secular perturbations and mean motion resonances lead to unstable regions, where not only planet formation is inhibited, but where a massive body would be ejected from the system on a hyperbolic orbit. The amplitude of these two main effects is different for S- and P-type planets, so that a comparison between the two populations might outline the influence of the companion star on the planet formation process. Unfortunately, at present the two populations (circumstellar or circumbinary) are not known equally well and different biases and uncertainties prevent a quantitative comparison. We also highlight the long-term dynamical evolution of both S and P-type systems and focus on how these different evolutions influence the final architecture of planetary systems in binaries.

scholarly journals Habitable Planet Formation in Binary Planetary Systems

2007 ◽  
Vol 666 (1) ◽  
pp. 436-446 ◽  
Author(s):  
Nader Haghighipour ◽  
Sean N. Raymond
Keyword(s):  
Planet Formation ◽  
Planetary Systems ◽  
Habitable Planet

scholarly journals Isolated Binaries and Triples in N-body Systems

1995 ◽  
Vol 164 ◽  
pp. 372-372
Author(s):  
J. Anosova ◽  
L. Kiseleva
Keyword(s):  
Globular Cluster ◽  
Binary Stars ◽  
Star Clusters ◽  
Dynamical Evolution ◽  
Time Interval ◽  
Galactic Field ◽  
Multiple Stars ◽  
Binary And Multiple Stars ◽  
Marked Tendency ◽  
Triple Stars

Stars show a marked tendency to form the systems of different multiplicity starting from the smallest systems as binary and triple stars up to clusters with a significantly larger number of objects (N ~ 107 for globular cluster s). Different investigators have used different methods of binary stars identificati on but modern observations give a frequency of binary and multiple stars in the Galactic field up to 70% Binary and multiple stars are also often present within star clusters. It is therefore very important to be able to identify such systems as rather isolated substructures in which the dynamical evolution is not significantly affected by other stars (at least, during some considerab le time interval).

scholarly journals Realistic collisional water transport during terrestrial planet formation

2020 ◽  
Vol 634 ◽  
pp. A76 ◽  
Author(s):  
C. Burger ◽  
Á. Bazsó ◽  
C. M. Schäfer
Keyword(s):  
Water Content ◽  
Water Transport ◽  
Planet Formation ◽  
Hybrid Approach ◽  
Dynamical Evolution ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Water Delivery ◽  
Hit And Run

Context. According to the latest theoretical and isotopic evidence, Earth’s water content originates mainly from today’s asteroid belt region, or at least from the same precursor material. This suggests that water was transported inwards to Earth, and to similar planets in their habitable zone, via (giant) collisions of planetary embryos and planetesimals during the chaotic final phase of planet formation. Aims. In current dynamical simulations water delivery to terrestrial planets is still studied almost exclusively by assuming oversimplified perfect merging, even though water and other volatiles are particularly prone to collisional transfer and loss. To close this gap we have developed a computational framework to model collisional water transport by direct combination of long-term N-body computations with dedicated 3D smooth particle hydrodynamics (SPH) collision simulations of differentiated, self-gravitating bodies for each event. Methods. Post-collision water inventories are traced self-consistently in the further dynamical evolution, in accretionary or erosive as well as hit-and-run encounters with two large surviving bodies, where besides collisional losses, water transfer between the encountering bodies has to be considered. This hybrid approach enables us for the first time to trace the full dynamical and collisional evolution of a system of approximately 200 bodies throughout the whole late-stage accretion phase (several hundred Myr). As a first application we choose a Solar System-like architecture with already formed giant planets on either circular or eccentric orbits and a debris disk spanning the whole terrestrial planet region (0.5–4 au). Results. Including realistic collision treatment leads to considerably different results than simple perfect merging, with lower mass planets and water inventories reduced regularly by a factor of two or more. Due to a combination of collisional losses and a considerably lengthened accretion phase, final water content, especially with giant planets on circular orbits, is strongly reduced to more Earth-like values, and closer to results with eccentric giant planets. Water delivery to potentially habitable planets is dominated by very few decisive collisions, mostly with embryo-sized or larger objects and only rarely with smaller bodies, at least if embryos have formed throughout the whole disk initially. The high frequency of hit-and-run collisions and the differences to predominantly accretionary encounters, such as generally low water (and mass) transfer efficiencies, are a crucial part of water delivery, and of system-wide evolution in general.

scholarly journals Planetary Systems Dynamics Eccentric patterns in debris disks & Planetary migration in binary systems

2013 ◽  
Vol 8 (S299) ◽  
pp. 212-213
Author(s):  
V. Faramaz ◽  
H. Beust ◽  
J.-C. Augereau ◽  
A. Bonsor ◽  
P. Thébault ◽  
...  
Keyword(s):  
Binary Systems ◽  
Planet Formation ◽  
Planetary Systems ◽  
Systems Dynamics ◽  
Debris Disks ◽  
Space Observatory ◽  
Herschel Space Observatory ◽  
Migration Mechanism ◽  
Planetary Migration

AbstractWe present some highlights of two ongoing investigations that deal with the dynamics of planetary systems. Firstly, until recently, observed eccentric patterns in debris disks were found in young systems. However recent observations of Gyr-old eccentric debris disks leads to question the survival timescale of this type of asymmetry. One such disk was recently observed in the far-IR by the Herschel Space Observatory around ζ2 Reticuli. Secondly, as a binary companion orbits a circumprimary disk, it creates regions where planet formation is strongly handicapped. However, some planets were detected in this zone in tight binary systems (γ Cep, HD 196885). We aim to determine whether a binary companion can affect migration such that planets are brought in these regions and focus in particular on the planetesimal-driven migration mechanism.

scholarly journals Probing the impact of stellar duplicity on the frequency of giant planets: Final results of our VLT/NACO survey

2010 ◽  
Vol 6 (S276) ◽  
pp. 409-410 ◽  
Author(s):  
Anne Eggenberger ◽  
Stéphane Udry ◽  
Gaël Chauvin ◽  
Thierry Forveille ◽  
Jean-Luc Beuzit ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Proper Motion ◽  
Binary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
The Other ◽  
Physical Association ◽  
Short Period ◽  
Solar Type ◽  
The Impact

AbstractIf it is commonly agreed that the presence of a (moderately) close stellar companion affects the formation and the dynamical evolution of giant planets, the frequency of giant planets residing in binary systems separated by less than 100 AU is unknown. To address this issue, we have conducted with VLT/NACO a systematic adaptive optics search for moderately close stellar companions to 130 nearby solar-type stars. According to the data from Doppler surveys, half of our targets host at least one planetary companion, while the other half show no evidence for short-period giant planets. We present here the final results of our survey, which include a new series of second-epoch measurements to test for common proper motion. The new observations confirm the physical association of two companion candidates and prove the unbound status of many others. These results strengthen our former conclusion that circumstellar giant planets are slightly less frequent in binaries with mean semimajor axes between 35 and 100 AU than in wider systems or around single stars.

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