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 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.

SPIRE beam steering mirror: a cryogenic 2 axis mechanism for the Herschel Space Observatory

2003 ◽  
Author(s):  
Ian Pain ◽  
Brian Stobie ◽  
Gillian S. Wright ◽  
T. A. Paul ◽  
Colin R. Cunningham
Keyword(s):  
Beam Steering ◽  
Space Observatory ◽  
Herschel Space Observatory

Exploring the dust ring in the circum-binary disc around GG Tau A

2021 ◽  
Author(s):  
Claudia Toci ◽  
Simone Ceppi ◽  
Nicolas Cuello ◽  
Giuseppe Lodato ◽  
Cristiano Longarini ◽  
...  
Keyword(s):  
Binary Systems ◽  
Planet Formation ◽  
Initial Conditions ◽  
Scattered Light ◽  
Complex Structure ◽  
Semimajor Axis ◽  
Continuum Emission ◽  
Orbital Parameter ◽  
Semi Major Axis ◽  
Multiple Systems

<p>Binaries and multiple systems are common among young stars (Reipurth et al. 2014). These stars are often surrounded by discs of gas and dust, formed due to the conservation of angular momentum of the collapsing cloud, thought to be the site of planet formation.<br />In the case of binary systems, three discs can form: an outer disc surrounding all the stars (called circumbinary disc), and two inner discs around the stars. As circumbinary planets have recently been discovered by Kepler (see e.g., Martin 2018, Bonavita & Desidera 2020), it is crucial to understand the dynamics and evolution of circumbinary discs to better understand the initial conditions of planet formation in multiple systems.<br />The GG Tau A system is an example of a young multiple T Tauri star. The binary is surrounded by a bright disc, observed in the continuum emission at different wavelengths (see e.g., Guilloteau et al. 1999; Dutrey et al. 2014; Phuong et al. 2020b) and in scattered light (e.g., Duchene et al. 2014, Keppler et al. 2020). The disc extends in the dust from 180 to 280 au from the center of mass, and in the gas up to 850 au. The inner (<180 au) part is depleted in gas and dust. Scattered light images show a complex structure in the inner part of the disc, with arcs and filamentary structures connecting the outer ring with the arcs and three shadows.<br />Two different configurations are possible fitting the proper motion data for the system: a co-planar case with a low eccentricity binary with a semi-major axis of 34 au, explored by Cazzoletti et al. 2017 and Keppler et al. 2020, and a misaligned case (i=30) with an eccentric binary (e=0.45) and a wider semimajor axis of 60 au (Aly et al.2018). At the state of the art, all these analyses focused on the gas dynamics only.<br />We will show the results of new 3D SPH simulations of dust and gas performed with the code PHANTOM, devised to test the two possible scenarios. We will describe the dynamics of the system in the two cases, comparing our models with observational results in order to better constraint the orbital parameter of the GG Tau A system. Our predictions will guide future observing campaigns and shed light on the complex evolution of discs in triple stellar systems.</p> <p> </p>

scholarly journals The Complete Census of 70 μm–Bright Debris Disks within “The Formation and Evolution of Planetary Systems”SpitzerLegacy Survey of Sun‐like Stars

2008 ◽  
Vol 677 (1) ◽  
pp. 630-656 ◽  
Author(s):  
Lynne A. Hillenbrand ◽  
John M. Carpenter ◽  
Jinyoung Serena Kim ◽  
Michael R. Meyer ◽  
Dana E. Backman ◽  
...  
Keyword(s):  
Planetary Systems ◽  
Debris Disks ◽  
Formation And Evolution

β Pictoris and other star spectra, in connection with planet formation

2004 ◽  
Vol 202 ◽  
pp. 300-307
Author(s):  
Anne. M. Lagrange ◽  
Herve Beust
Keyword(s):  
Planet Formation ◽  
Planetary System ◽  
Present Knowledge ◽  
Debris Disks ◽  
System Activity ◽  
Pms Stars

We review here the present knowledge on the gaseous phases of debris disks found around MS and old PMS stars, and make an attempt to connect them with planetary system activity.

scholarly journals PLANET FORMATION IN HIGHLY INCLINED BINARY SYSTEMS. I. PLANETESIMALS JUMP INWARD AND PILE UP

2011 ◽  
Vol 735 (1) ◽  
pp. 10 ◽  
Author(s):  
Ji-Wei Xie ◽  
Matthew J. Payne ◽  
Philippe Thébault ◽  
Ji-Lin Zhou ◽  
Jian Ge
Keyword(s):  
Binary Systems ◽  
Planet Formation ◽  
Pile Up

Migration of Low-Mass Planets

2021 ◽  
Author(s):  
Frédéric S. Masset
Keyword(s):  
Aerodynamic Drag ◽  
Semimajor Axis ◽  
Planetary Systems ◽  
High Mass ◽  
Reverse Migration ◽  
Low Viscosity ◽  
Kepler Mission ◽  
Sensitive Dependence ◽  
Low Mass ◽  
Planetary Migration

Planet migration is the variation over time of a planet’s semimajor axis, leading to either a contraction or an expansion of the orbit. It results from the exchange of energy and angular momentum between the planet and the disk in which it is embedded during its formation and can cause the semimajor axis to change by as much as two orders of magnitude over the disk’s lifetime. The migration of forming protoplanets is an unavoidable process, and it is thought to be a key ingredient for understanding the variety of extrasolar planetary systems. Although migration occurs for protoplanets of all masses, its properties for low-mass planets (those having up to a few Earth masses) differ significantly from those for high-mass planets. The torque that is exerted by the disk on the planet is composed of different contributions. While migration was first thought to be invariably inward, physical processes that are able to halt or even reverse migration were later uncovered, leading to the realization that the migration path of a forming planet has a very sensitive dependence on the underlying disk parameters. There are other processes that go beyond the case of a single planet experiencing smooth migration under the disk’s tide. This is the case of planetary migration in low-viscosity disks, a fashionable research avenue because protoplanetary disks are thought to have very low viscosity, if any, over most of their planet-forming regions. Such a process is generally significantly chaotic and has to be tackled through high-resolution numerical simulations. The migration of several low-mass planets is also is a very fashionable topic, owing to the discovery by the Kepler mission of many multiple extrasolar planetary systems. The orbital properties of these systems suggest that at least some of them have experienced substantial migration. Although there have been many studies to account for the orbital properties of these systems, there is as yet no clear picture of the different processes that shaped them. Finally, some recently unveiled processes could be important for the migration of low-mass planets. One process is aero-resonant migration, in which a swarm of planetesimals subjected to aerodynamic drag push a planet inward when they reach a mean-motion resonance with the planet, while another process is based on so-called thermal torques, which arise when thermal diffusion in the disk is taken into account, or when the planet, heated by accretion, releases heat into the ambient gas.

scholarly journals Influence of migration models and thermal torque on planetary growth in the pebble accretion scenario

2020 ◽  
Vol 637 ◽  
pp. A11 ◽  
Author(s):  
Thomas Baumann ◽  
Bertram Bitsch
Keyword(s):  
Planet Formation ◽  
Major Axis ◽  
Type I ◽  
Semi Major Axis ◽  
Disk Structure ◽  
Accretion Rates ◽  
Low Mass ◽  
Planetary Migration ◽  
Gas Accretion ◽  
Outward Migration

Low-mass planets that are in the process of growing larger within protoplanetary disks exchange torques with the disk and change their semi-major axis accordingly. This process is called type I migration and is strongly dependent on the underlying disk structure. As a result, there are many uncertainties about planetary migration in general. In a number of simulations, the current type I migration rates lead to planets reaching the inner edge of the disk within the disk lifetime. A new kind of torque exchange between planet and disk, the thermal torque, aims to slow down inward migration via the heating torque. The heating torque may even cause planets to migrate outwards, if the planetary luminosity is large enough. Here, we study the influence on planetary migration of the thermal torque on top of previous type I models. We find that the formula of Paardekooper et al. (2011, MNRAS, 410, 293) allows for more outward migration than that of Jiménez & Masset (2017, MNRAS, 471, 4917) in most configurations, but we also find that planets evolve to very similar mass and final orbital radius using both formulae in a single planet-formation scenario, including pebble and gas accretion. Adding the thermal torque can introduce new, but small, regions of outwards migration if the accretion rates onto the planet correspond to typical solid accretion rates following the pebble accretion scenario. If the accretion rates onto the planets become very large, as could be the case in environments with large pebble fluxes (e.g., high-metallicity environments), the thermal torque can allow more efficient outward migration. However, even then, the changes for the final mass and orbital positions in our planet formation scenario are quite small. This implies that for single planet evolution scenarios, the influence of the heating torque is probably negligible.

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