Related papers: Failed Oort Clouds and Planetary Migration
Circumbinary gas disks are often observed to be misaligned to the binary orbit suggesting that planet formation may proceed in a misaligned disk. With N-body simulations we consider the formation of circumbinary terrestrial planets from a…
A new so-called `gravitational loss-cone instability' in stellar systems has recently been investigated theoretically in the framework of linear perturbation theory and proved to be potentially important in understanding the physical…
Hundreds of circumstellar disks in the Orion nebula are being rapidly destroyed by the intense ultraviolet radiation produced by nearby bright stars. These young, million-year-old disks may not survive long enough to form planetary systems.…
Stars form by gravoturbulent fragmentation of interstellar gas clouds. The supersonic turbulence ubiquitously observed in Galactic molecular gas generates strong density fluctuations with gravity taking over in the densest and most massive…
The formation of massive stellar clusters in turbulent molecular clouds is investigated. We include artificial star formation and energy feedback of newly born stars. The obtained systems are not likely to survive. Case studies to determine…
During the fragmentation and collapse of a molecular cloud, it is expected to have close encounters between (proto)stellar objects that can lead to the ejection of a fraction of them as runaway objects. However, the duration and the…
The migration of the giant planets due to the scattering of planetesimals causes powerful resonances to move through the asteroid belt and the terrestrial planet region. Exactly when and how the giant planets migrated is not well known. In…
Planet Planet scattering is a leading dynamical mechanism invoked to explain the present orbital distribution of exoplanets. Many stars belong to binary systems, therefore it is important to understand how this mechanism works in presence…
We find a deficiency of binary stars moving on strongly retrograde Galactic orbits. No binary deficiencies are seen for U or W velocities, however. From theoretical analyses, we rule out preferential disruption of pre-existing binary stars…
Current protoplanetary dust coagulation theory does not predict dry silicate planetesimals, in tension with the Earth. While remedies to this predicament have been proposed, they have generally failed numerical studies, or are in tension…
Core Accretion, the most widely accepted scenario for planet formation, postulates existence of km-sized solid bodies, called planetesimals, arranged in a razor-thin disc in the earliest phases of planet formation. In the Tidal Downsizing…
Models of the zodiacal cloud's thermal emission and sporadic meteoroids suggest Jupiter-family comets (JFCs) as the dominant source of interplanetary dust. However, comet sublimation is insufficient to sustain the quantity of dust presently…
Planets are common objects in the Universe, observationally as well as theoretically. However, the standard theory of their formation encounters many difficulties, such as dust fall and disk lifetime problems. We positively analyze them,…
Motivated by the recent discovery of massive planets on wide orbits, we present a mechanism for the formation of such planets via disk fragmentation in the embedded phase of star formation. In this phase, the forming disk intensively…
The effects of multi-layered clouds in the atmospheres of Earth-like planets orbiting different types of stars are studied. The radiative effects of cloud particles are directly correlated with their wavelength-dependent optical properties.…
The modestly eccentric and non-coplanar orbits of the giant planets pose a challenge to solar system formation theories which generally indicate that the giant planets emerged from the protoplanetary disk in nearly perfectly circular and…
Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures,…
Gravitational torques between a planet and gas in the protoplanetary disk result in orbital migration of the planet, and are likely to play an important role in the formation and early evolution of planetary systems. For masses comparable…
Tidal disruption events are common in the Universe, which may occur in various compact star systems and could account for many astrophysical phenomena. Depending on the separation between the central compact star and its companion, either a…
The cratering record on the Earth and Moon shows that our planet has been exposed to high velocity impacts for much or all of its existence. Some of these craters were produced by the impact of long period comets (LPCs). These probably…