Results 11 to 20 of about 832 (184)

Gravoturbulent Formation of Planetesimals [PDF]

open access: yesThe Astrophysical Journal, 2006
We explore the effect of magnetorotational turbulence on the dynamics and concentrations of boulders in local box simulations of a sub-Keplerian protoplanetary disc. The solids are treated as particles each with an independent space coordinate and velocity. We find that the turbulence has two effects on the solids.
Johansen, Anders   +2 more
openaire   +2 more sources

Dynamics and accretion of planetesimals [PDF]

open access: yesProgress of Theoretical and Experimental Physics, 2012
We review the basic dynamics and accretion of planetesimals by showing N-body simulations. The orbits of planetesimals evolve through two-body gravitational relaxation: viscous stirring increases the random velocity and dynamical friction realizes the equiparation of the random energy.
Kokubo, Eiichiro, Ida, Shigeru
openaire   +2 more sources

Binary Formation in Planetesimal Disks. I. Equal Mass Planetesimals [PDF]

open access: yesPublications of the Astronomical Society of Japan, 2011
As of April 2010, 48 TNO (trans-Neptunian Object) binaries have been found. This is about 6% of known TNOs. However, in previous theoretical studies of planetary formation in the TNO region, the effect of binary formation has been neglected. TNO binaries can be formed through a variety of mechanisms, such as a three-body process, dynamical friction on ...
Daisaka, Junko K.   +2 more
openaire   +2 more sources

Forbidden planetesimals

open access: yesAstronomy & Astrophysics, 2023
Planetesimals are born fragile and are subject to destruction by wind erosion as they move through the gas of a protoplanetary disk. In microgravity experiments, we determined the shear stress necessary for erosion of a surface consisting of 1 mm dust pebbles down to 1 Pa ambient pressure. This is directly applicable to protoplanetary disks.
L. Schönau   +7 more
openaire   +3 more sources

PLANETESIMAL DISK MICROLENSING [PDF]

open access: yesThe Astrophysical Journal, 2009
Motivated by debris disk studies, we investigate the gravitational microlensing of background starlight by a planetesimal disk around a foreground star. We use dynamical survival models to construct a plausible example of a planetesimal disk and study its microlensing properties using established ideas of microlensing by small bodies. When a solar-type
Heng, Kevin, Keeton, Charles R.
openaire   +2 more sources

Formation of Comets

open access: yesUniverse, 2022
Questions regarding how primordial or pristine the comets of the solar system are have been an ongoing controversy. In this review, we describe comets’ physical evolution from dust and ice grains in the solar nebula to the contemporary small bodies in ...
Jürgen Blum   +2 more
doaj   +1 more source

Planetesimal Population Synthesis: Pebble Flux-regulated Planetesimal Formation [PDF]

open access: yesThe Astrophysical Journal, 2019
Abstract We propose an expression for a local planetesimal formation rate proportional to the instantaneous radial pebble flux. The result—a radial planetesimal distribution—can be used as an initial condition to study the formation of planetary embryos.
Christian T. Lenz   +2 more
openaire   +3 more sources

Interstellar Planetesimals

open access: yes, 2023
During the formation of our solar system, a large number of planetesimals were ejected into interstellar space by gravitational encounters with the planets. Debris disks observations and numerical simulations indicate that many other planetary systems, now known to be quite common, would have undergone a similar dynamical clearing process.
openaire   +2 more sources

PLANETESIMAL COMPOSITIONS IN EXOPLANET SYSTEMS [PDF]

open access: yesThe Astrophysical Journal, 2012
We have used recent surveys of the composition of exoplanet host stars to investigate the expected composition of condensed material in planetesimals formed beyond the snow line in the circumstellar nebulae of these systems. Of the major solid forming elements, we find that, as for the Sun, the C and O abundances (and particularly the C/O abundance ...
Johnson, T.V.   +3 more
openaire   +3 more sources

Binary formation in planetesimal disks. II. Planetesimals with a mass spectrum [PDF]

open access: yesPublications of the Astronomical Society of Japan, 2014
Abstract Many massive objects have been found in the outer region of the solar system. How they were formed and evolved has not been well understood, although there have been intensive studies of the accretion process of terrestrial planets. One of the mysteries is the existence of binary planetesimals with near-equal mass components and
Kominami, Junko D., Makino, Junichiro
openaire   +2 more sources

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