Related papers: Euler, Jacobi, and Missions to Comets and Asteroid…
Vortices are readily produced by hydrodynamical instabilities, such as the Rossby wave instability, in protoplanetary disks. However, large-scale asymmetries indicative of dust-trapping vortices are uncommon in sub-millimeter continuum…
The recent discovery of narrow rings around minor bodies has raised many questions regarding their origin and current dynamics. Sharp ring boundaries seem indicative of shepherding moonlets, but none have been found. All rings lie close to…
Recent observations of several protoplanetary discs have found evidence of departures from flat, circular motion in the inner regions of the disc. One possible explanation for these observations is a disc warp, which could be induced by a…
We review results on the dynamics of warped gaseous discs. We consider tidal perturbation of a Keplerian disc by a companion star orbiting in a plane inclined to the disc. The perturbation induces the precession of the disc, and thus of any…
We investigate collective phenomena with rotationally driven spinners of concave shape. Each spinner experiences a constant internal torque in either a clockwise or counterclockwise direction. Although the spinners are modeled as hard,…
The Kepler Mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the…
Observations of hot Jupiters around solar-type stars with very short orbital periods (~day) suggest that tidal dissipation in such stars is not too efficient so that these planets can survive against rapid orbital decay. This is consistent…
Dust particles in protoplanetary disks, lacking support from pressure, rotate at velocities exceeding those of the surrounding gas. Consequently, they experience a head-wind from the gas that drives them toward the central star. Radial…
The orbital architecture of the Solar System is thought to have been sculpted by a dynamical instability among the giant planets. During the instability a primordial outer disk of planetesimals was destabilized and ended up on…
When viewed from Earth, most of what we observe of a comet is dust. The influence of solar radiation pressure on the trajectories of dust particles depends on their cross-section to mass ratio. Hence solar radiation pressure acts like a…
We present the results of relativistic smoothed particle hydrodynamics simulations of tidal disruptions of stars by rotating supermassive black holes, for a wide range of impact parameters and black hole spins. For deep encounters, we find…
About 10% of the observed asteroids have rotational periods lower than P = 3 h and they seem to be relatively close to the spin barrier. Yet, the rotation has often been neglected in simulations of asteroid collisions. To determine the…
Magnetic interactions between a protostar and its accretion disc tend to induce warping in the disc and produce secular changes in the stellar spin direction, so that the spin axis may not always be perpendicular to the disc. This may help…
The gravitational instability model of planet/brown dwarf formation proposes that protostellar discs can fragment into objects with masses above a few Jupiter masses at large semimajor axis. Tidal downsizing may reduce both the object mass…
A polarizable body moving in an external electromagnetic field will slow down. This effect is referred to as radiation damping and is analogous to Doppler cooling in atomic physics. Using the principles of special relativity we derive an…
Planets form in active protoplanetary disks that sustain stellar jets. Momentum loss from the jet system may excite the planets' orbital eccentricity and inclination (Namouni 2005, AJ 130, 280). Evaluating quantitatively the effects of such…
Most Neptune-mass planets in close-in orbits (orbital periods less than a few days) present nonzero eccentricity, typically around 0.15. This is somehow unexpected, as these planets undergo strong tidal dissipation that should circularize…
Rotation axis variation due to spin orbit resonance: conference report; keywords: planetary precession, rigid body, chaos, KAM, Arnold diffusion, averaging, celestial mechanics, classical mechanics, large deviations
This paper deals with the application of the creep tide theory (Ferraz-Mello, Cel. Mech. Dyn. Astron. vol. 116, 109, 2013) to the study of the rotation of stars hosting massive close-in planets. The stars have nearly the same tidal…
There is a correlation between the components of the YORP effect of most asteroids, which drives the obliquity and spin rate of the affected bodies in a consistent pattern. This allows for a clear and unambiguous picture for how the spin…