scholarly journals EFFECTS OF DYNAMICAL EVOLUTION OF GIANT PLANETS ON THE DELIVERY OF ATMOPHILE ELEMENTS DURING TERRESTRIAL PLANET FORMATION

2016 ◽  
Vol 818 (1) ◽  
pp. 15 ◽  
Author(s):  
Soko Matsumura ◽  
Ramon Brasser ◽  
Shigeru Ida
Keyword(s):  
Planet Formation ◽  
Dynamical Evolution ◽  
Terrestrial Planet ◽  
Giant Planets

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 Forming terrestrial planets and delivering water

2015 ◽  
Vol 11 (A29B) ◽  
pp. 427-430
Author(s):  
Kevin J. Walsh
Keyword(s):  
Planet Formation ◽  
Semimajor Axis ◽  
Giant Planet ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Terrestrial Planets ◽  
The Earth ◽  
Building Models ◽  
Rich Material

AbstractBuilding models capable of successfully matching the Terrestrial Planet's basic orbital and physical properties has proven difficult. Meanwhile, improved estimates of the nature of water-rich material accreted by the Earth, along with the timing of its delivery, have added even more constraints for models to match. While the outer Asteroid Belt seemingly provides a source for water-rich planetesimals, models that delivered enough of them to the still-forming Terrestrial Planets typically failed on other basic constraints - such as the mass of Mars.Recent models of Terrestrial Planet Formation have explored how the gas-driven migration of the Giant Planets can solve long-standing issues with the Earth/Mars size ratio. This model is forced to reproduce the orbital and taxonomic distribution of bodies in the Asteroid Belt from a much wider range of semimajor axis than previously considered. In doing so, it also provides a mechanism to feed planetesimals from between and beyond the Giant Planet formation region to the still-forming Terrestrial Planets.

scholarly journals Terrestrial planet formation in extra-solar planetary systems

2007 ◽  
Vol 3 (S249) ◽  
pp. 233-250 ◽  
Author(s):  
Sean N. Raymond
Keyword(s):  
Final Stage ◽  
Planet Formation ◽  
Giant Planet ◽  
Terrestrial Planet ◽  
Circumstellar Disks ◽  
Giant Planets ◽  
Terrestrial Planets ◽  
Low Mass Stars ◽  
Low Mass ◽  
Rocky Planets

AbstractTerrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called “planetary embryos”. Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding zones and the amount of radial mixing that occurs. The main factors that influence terrestrial planet formation are the mass and surface density profile of the disk, and the perturbations from giant planets and binary companions if they exist. Simple accretion models predicts that low-mass stars should form small, dry planets in their habitable zones. The migration of a giant planet through a disk of rocky bodies does not completely impede terrestrial planet growth. Rather, “hot Jupiter” systems are likely to also contain exterior, very water-rich Earth-like planets, and also “hot Earths”, very close-in rocky planets. Roughly one third of the known systems of extra-solar (giant) planets could allow a terrestrial planet to form in the habitable zone.

scholarly journals Can narrow discs in the inner Solar system explain the four terrestrial planets?

2020 ◽  
Vol 496 (3) ◽  
pp. 3688-3699 ◽  
Author(s):  
Patryk Sofia Lykawka
Keyword(s):  
Solar System ◽  
Planet Formation ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
System Model ◽  
Terrestrial Planets ◽  
P System ◽  
Orbital Mass ◽  
System A ◽  
System 2

ABSTRACT A successful Solar system model must reproduce the four terrestrial planets. Here, we focus on (1) the likelihood of forming Mercury and the four terrestrial planets in the same system (a 4-P system); (2) the orbital properties and masses of each terrestrial planet; and (3) the timing of Earth’s last giant impact and the mass accreted by our planet thereafter. Addressing these constraints, we performed 450 N-body simulations of terrestrial planet formation based on narrow protoplanetary discs with mass confined to 0.7–1.0 au. We identified 164 analogue systems, but only 24 systems contained Mercury analogues, and eight systems were 4-P ones. We found that narrow discs containing a small number of embryos with individual masses comparable to that of Mars and the giant planets on their current orbits yielded the best prospects for satisfying those constraints. However, serious shortcomings remain. The formation of Mercury analogues and 4-P systems was too inefficient (5 per cent and 2 per cent, respectively), and most Venus-to-Earth analogue mass ratios were incorrect. Mercury and Venus analogues also formed too close to each other (∼0.15–0.21 au) compared to reality (0.34 au). Similarly, the mutual distances between the Venus and Earth analogues were greater than those observed (0.34 versus 0.28 au). Furthermore, the Venus–Earth pair was not reproduced in orbital-mass space statistically. Overall, our results suggest serious problems with using narrow discs to explain the inner Solar system. In particular, the formation of Mercury remains an outstanding problem for terrestrial planet formation models.

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.

The Role of Giant Planets in Terrestrial Planet Formation

2003 ◽  
Vol 125 (5) ◽  
pp. 2692-2713 ◽  
Author(s):  
Harold F. Levison ◽  
Craig Agnor
Keyword(s):  
Planet Formation ◽  
Terrestrial Planet ◽  
Giant Planets

scholarly journals High-precision analysis of binary stars with planets

2019 ◽  
Vol 625 ◽  
pp. A39 ◽  
Author(s):  
C. Saffe ◽  
E. Jofré ◽  
P. Miquelarena ◽  
M. Jaque Arancibia ◽  
M. Flores ◽  
...  
Keyword(s):  
Binary System ◽  
High Precision ◽  
Binary Stars ◽  
Planet Formation ◽  
Giant Planet ◽  
Dynamical Evolution ◽  
Terrestrial Planet ◽  
Condensation Temperature ◽  
The Sun ◽  
First Time

Aims. We explore for the first time the probable chemical signature of planet formation in the remarkable binary system HD 106515. Star A hosts a massive long-period planet with ~9 MJup detected by radial velocity, while there is no planet detected at the B star. We also refine stellar and planetary parameters by using non-solar-scaled opacities when modelling the stars. Methods. We carried out a simultaneous determination of stellar parameters and abundances by applying for the first time non-solar-scaled opacities in this binary system, in order to reach the highest possible precision. We used a line-by-line strictly differential approach, using the Sun and then the A star as reference. Stellar parameters were determined by imposing an ionization and excitation balance of Fe lines, with an updated version of the FUNDPAR program, ATLAS12 model atmospheres, and the MOOG code. Opacities for an arbitrary composition were calculated through the opacity sampling method. The chemical patterns were compared with solar-twins condensation temperature Tc trends from the literature and also mutually between both stars. We take the opportunity to compare and discuss the results of the classical solar-scaled method and the high-precision procedure applied here. Results. Stars A and B in the binary system HD 106515 do not seem to be depleted in refractory elements, which is different when comparing the Sun with solar twins. The terrestrial planet formation would have been less efficient in the stars of this binary system. Together with HD 80606/7, this is the second binary system that does not seem to present a (terrestrial) signature of planet formation, when both systems host an eccentric giant planet. This is in agreement with numerical simulations, where the early dynamical evolution of eccentric giant planets clears out most of the possible terrestrial planets in the inner zone. We refined the stellar mass, radius, and age for both stars and found a notable difference of ~78% in R⋆ compared to previous works. We also refined the planet mass to mp sini = 9.08 ± 0.20 MJup, which differs by ~6% compared with the literature. In addition, we showed that the non-solar-scaled solution is not compatible with the classical solar-scaled method, and some abundance differences are comparable to non-local thermodynamic equilibrium (NLTE) or galactic chemical evolution (GCE) effects especially when using the Sun as reference. Therefore, we encourage the use of non-solar-scaled opacities in high-precision studies such as the detection of Tc trends.

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.

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