scholarly journals Terrestrial planet formation in low-mass disks: dependence with initial conditions

2014 ◽  
Vol 9 (S310) ◽  
pp. 218-219
Author(s):  
M. P. Ronco ◽  
G. C. de Elía ◽  
O. M. Guilera
Keyword(s):  
Gas Phase ◽  
Analytical Model ◽  
Ad Hoc ◽  
Planet Formation ◽  
Initial Conditions ◽  
Planetary Systems ◽  
Terrestrial Planet ◽  
Initial Distribution ◽  
Protoplanetary Disk ◽  
Low Mass

AbstractIn general, most of the studies of terrestrial-type planet formation typically use ad hoc initial conditions. In this work we improved the initial conditions described in Ronco & de Elía (2014) starting with a semi-analytical model wich simulates the evolution of the protoplanetary disk during the gas phase. The results of the semi-analytical model are then used as initial conditions for the N-body simulations. We show that the planetary systems considered are not sensitive to the particular initial distribution of embryos and planetesimals and thus, the results are globally similar to those found in the previous work.

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 N-body Simulations of Planet Formation

2003 ◽  
Vol 208 ◽  
pp. 25-35 ◽  
Author(s):  
Shigeru Ida ◽  
Eiichiro Kokubo ◽  
Junko Kominami
Keyword(s):  
Final Stage ◽  
Planet Formation ◽  
Planetary Systems ◽  
Terrestrial Planet ◽  
The Other ◽  
Other Hand ◽  
Giant Impacts ◽  
Gas Accretion

Accretion from many small planetesimals to planets is reviewed. Solid protoplanets accrete through runaway and oligarchic growth until they become isolated. The isolation mass of protoplanets in terrestrial planet region is about 0.1-0.2 Earth mass, which suggests giant impacts among the protoplanets in the final stage of terrestrial planet formation. On the other hand, the isolation mass in Jupiter's and Saturn's orbits is about a few to 5 Earth masses, which may be massive enough to trigger gas accretion onto the cores. The isolation mass in Uranus and Neptune's orbits is as large as their present cores. Extending the above arguments to extrasolar planetary systems that are formed from disks with various initial masses, we also discuss diversity of extrasolar planetary systems.

scholarly journals Terrestrial Planet Formation: Dynamical Shake-up and the Low Mass of Mars

2017 ◽  
Vol 153 (5) ◽  
pp. 216 ◽  
Author(s):  
Benjamin C. Bromley ◽  
Scott J. Kenyon
Keyword(s):  
Planet Formation ◽  
Terrestrial Planet ◽  
Low Mass

scholarly journals SMA and ALMA studies of protoplanetary disk formation around low-mass protostars

2015 ◽  
Vol 11 (S315) ◽  
pp. 126-129
Author(s):  
Shigehisa Takakuwa ◽  
Nagayoshi Ohashi ◽  
Hsi-Wei Yen ◽  
Ti-Lin Chou ◽  
Kazuya Saigo ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Large Scale ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Protoplanetary Disk ◽  
Evolutionary Trend ◽  
Disk Formation ◽  
Systematic Survey ◽  
Angular Momenta ◽  
Low Mass

AbstractWe report our systematic survey observations of protostellar sources with the SubMillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA). The purpose of our survey is to investigate formation mechanism of protoplanetary disks, precursors of planetary systems, out of ~1000 AU-scale protostellar envelopes surrounding the protostars. We found that in the early protostars (B335, NGC1333 IRAS 4B), the envelopes do not show significant rotating motions but infalling motions toward the central protostars. In more evolved protostars (L1527 IRS, L1448-mm, L1551 IRS 5), the envelopes are infalling and rotating with the conserved specific angular momenta (that is, vrot ∝ r−1). In most evolved sources (L1551 NE, TMC-1A, L1489 IRS) large-scale (≳100 AU) disks in Keplerian rotation or protoplanetary disks are evident. These results demonstrate a systematic evolutionary trend of envelope gas motions toward the disk formation.

scholarly journals Planetary systems formation and the diversity of extrasolar systems

2010 ◽  
Vol 6 (S276) ◽  
pp. 441-442
Author(s):  
Yamila Miguel ◽  
Octavio M. Guilera ◽  
Adrián Brunini
Keyword(s):  
Analytical Model ◽  
System Architecture ◽  
Planetary System ◽  
Initial Conditions ◽  
Planetary Systems ◽  
Large Sample ◽  
Migration Rates ◽  
Extrasolar Systems ◽  
Planetary Migration ◽  
The Universe

AbstractWith the end of answer questions as, how common are planetary systems like our own in the Universe? and What is the diversity of planetary systems that we could find in the universe?, we develop a semi-analytical model for computing planetary systems formation and consider different initial conditions for generating a large sample of planetary systems, which is analysed statistically. We explore the effects in the planetary system architecture of assuming different initial disc profiles and planetary migration rates.

scholarly journals The Diversity of Extrasolar Terrestrial Planets

2009 ◽  
Vol 5 (S265) ◽  
pp. 399-402
Author(s):  
Jade C. Bond ◽  
Dante S. Lauretta ◽  
David P. O'Brien
Keyword(s):  
Chemical Equilibrium ◽  
Planet Formation ◽  
Planetary Systems ◽  
Solid Material ◽  
Terrestrial Planet ◽  
Building Blocks ◽  
Terrestrial Planets ◽  
Dynamical Models ◽  
Diverse Range ◽  
Host Stars

AbstractExtrasolar planetary host stars are enriched in key planet-building elements. These enrichments have the potential to drastically alter the building blocks available for terrestrial planet formation. Here we report on the combination of dynamical models of late-stage terrestrial planet formation within known extrasolar planetary systems with chemical equilibrium models of the composition of solid material within the disk. This allows us to constrain the bulk elemental composition of extrasolar terrestrial planets. A wide variety of resulting planetary compositions exist, ranging from those that are essentially “Earth-like”, containing metallic Fe and Mg-silicates, to those that are dominated by graphite and SiC. This implies that a diverse range of terrestrial planets are likely to exist within extrasolar planetary systems.

scholarly journals A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary

Science ◽  
2014 ◽  
Vol 345 (6192) ◽  
pp. 46-49 ◽  
Author(s):  
A. Gould ◽  
A. Udalski ◽  
I.-G. Shin ◽  
I. Porritt ◽  
J. Skowron ◽  
...  
Keyword(s):  
Binary Systems ◽  
Planet Formation ◽  
Binary Star ◽  
Terrestrial Planet ◽  
Search Strategies ◽  
The Sun ◽  
Star System ◽  
Low Mass ◽  
Formation And Evolution ◽  
Binary Star System

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth’s) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet’s temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

scholarly journals Diverse outcomes of planet formation and composition around low-mass stars and brown dwarfs

2019 ◽  
Author(s):  
Y Miguel ◽  
A Cridland ◽  
C W Ormel ◽  
J J Fortney ◽  
S Ida
Keyword(s):  
Planet Formation ◽  
Planetary Systems ◽  
Brown Dwarfs ◽  
Population Synthesis ◽  
Optimal Conditions ◽  
Low Mass Stars ◽  
Water Fraction ◽  
Low Mass ◽  
M Stars ◽  
Mass Form

Abstract The detection of Earth-size exoplanets around low-mass stars –in stars such as Proxima Centauri and TRAPPIST-1– provide an exceptional chance to improve our understanding of the formation of planets around M stars and brown dwarfs. We explore the formation of such planets with a population synthesis code based on a planetesimal-driven model previously used to study the formation of the Jovian satellites. Because the discs have low mass and the stars are cool, the formation is an inefficient process that happens at short periods, generating compact planetary systems. Planets can be trapped in resonances and we follow the evolution of the planets after the gas has dissipated and they undergo orbit crossings and possible mergers. We find that formation of planets above Mars mass and in the planetesimal accretion scenario, is only possible around stars with masses M⋆ ≥ 0.07Msun and discs of Mdisc ≥ 10−2 Msun. We find that planets above Earth-mass form around stars with masses larger than 0.15 Msun, while planets larger than 5 M⊕ do not form in our model, even not under the most optimal conditions (massive disc), showing that planets such as GJ 3512b form with another, more efficient mechanism. Our results show that the majority of planets form with a significant water fraction; that most of our synthetic planetary systems have 1, 2 or 3 planets, but planets with 4,5,6 and 7 planets are also common, confirming that compact planetary systems with many planets should be a relatively common outcome of planet formation around small stars.

scholarly journals Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): A close low-mass companion to ET Cha

2020 ◽  
Vol 642 ◽  
pp. A119
Author(s):  
C. Ginski ◽  
F. Ménard ◽  
Ch. Rab ◽  
E. E. Mamajek ◽  
R. G. van Holstein ◽  
...  
Keyword(s):  
Planet Formation ◽  
Thermal Emission ◽  
Initial Conditions ◽  
Scattered Light ◽  
Primary Component ◽  
Young Stars ◽  
High Contrast ◽  
Evolution Study ◽  
Disk Evolution ◽  
Low Mass

Context. To understand the formation of planetary systems, it is important to understand the initial conditions of planet formation, that is, the young gas-rich planet forming disks. Spatially resolved, high-contrast observations are of particular interest since substructures in disks that are linked to planet formation can be detected. In addition, we have the opportunity to reveal close companions or even planets in formation that are embedded in the disk. Aims. In this study, we present the first results of the Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS), an ESO/SPHERE large program that is aimed at studying disk evolution in scattered light, mainly focusing on a sample of low-mass stars (< 1 M⊙) in nearby (∼200 pc) star-forming regions. In this particular study, we present observations of the ET Cha (RECX 15) system, a nearby “old” classical T Tauri star (5−8 Myr, ∼100 pc), which is still strongly accreting. Methods. We used SPHERE/IRDIS in the H-band polarimetric imaging mode to obtain high spatial resolution and high-contrast images of the ET Cha system to search for scattered light from the circumstellar disk as well as thermal emission from close companions. We additionally employed VLT/NACO total intensity archival data of the system taken in 2003. Results. Here, we report the discovery, using SPHERE/IRDIS, of a low-mass (sub)stellar companion to the η Cha cluster member ET Cha. We estimate the mass of this new companion based on photometry. Depending on the system age, it is either a 5 Myr, 50 MJup brown dwarf or an 8 Myr, 0.10 M⊙ M-type, pre-main-sequence star. We explore possible orbital solutions and discuss the recent dynamic history of the system. Conclusions. Independent of the precise companion mass, we find that the presence of the companion likely explains the small size of the disk around ET Cha. The small separation of the binary pair indicates that the disk around the primary component is likely clearing from the outside in, which explains the high accretion rate of the system.

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