Related papers: Ejected Surface Regolith as a Potential Source Mat…

We discuss the nature of rings that may exist around extrasolar planets. Taking the general properties of rings around the gas giants in the Solar System, we infer the likely properties of rings around exoplanets that reside inside the ice…

Models are developed to simulate lightcurves of stars dimmed by transiting exoplanets with and without rings. These models are then applied to \textit{Kepler} photometry to search for planetary rings in a sample of 21 exoplanets, mostly hot…

We propose a generic mechanism for the formation of narrow rings in rotating systems. For this purpose we use a system of discs rotating about a common center lying well outside the discs. A discussion of this system shows that narrow rings…

More than a half of asteroids in the main belt have irregular shapes with the ratios of the minor to major axis lengths less than 0.6. One of the mechanisms to create such shapes is collisions between asteroids. The relationship between…

Erosive collisions among planetary embryos in the inner solar system can lead to multiple remnant bodies, varied in mass, composition and residual velocity. Some of the smaller, unbound debris may become available to seed the main asteroid…

Most major planetary bodies in the solar system rotate in the same direction as their orbital motion: their spin is prograde. Theoretical studies to explain the direction as well as the magnitude of the spin vector have had mixed success.…

Close to the Roche radius of a white dwarf (WD), an asteroid on a circular orbit sheds material that then adopts a very similar orbit. Observations of the resulting debris show a periodic behavior and changes in flux on short timescales,…

All of the known circumbinary planets are large (> 3 Earth radii). Whilst observational biases may account for this dearth of small planets, in this paper we propose a theoretical explanation. Most of the known planets are near the…

In the local (redshift z~0) Universe, collisional ring galaxies make up only ~0.01% of galaxies and are formed by head-on galactic collisions that trigger radially propagating density waves. These striking systems provide key snapshots for…

Motivated by recent visits from interstellar comets, along with continuing discoveries of minor bodies in orbit of the Sun, this paper studies the capture of objects on initially hyperbolic orbits by our solar system. Using an ensemble of…

The ejecta discharged by impacting meteorites can redistribute a planetary ring's mass and angular momentum. This `ballistic transport' of ring properties instigates a linear instability that could generate the 100--1000-km undulations…

Most of the planetary systems discovered around binary stars are located at approximately three semi-major axes from the barycentre of their system, curiously close to low-order mean-motion resonances (MMRs). The formation mechanism of…

Cybele asteroids constitute an appealing reservoir of primitive material genetically linked to the outer Solar System, and the physical properties of the largest members can be readily accessed by large telescopes. We took advantage of the…

We present the discovery of ringlike diffuse radio emission structures in the peripheral regions of the Bullet cluster 1E 0657$-$55.8. Ring formations are spanning between 1--3 Mpc away from the center of the cluster, significantly further…

Gravitational interactions in star-forming regions are capable of disrupting and destroying planetary systems, as well as creating new ones. In particular, a planet can be stolen, where it is directly exchanged between passing stars during…

In an effort to understand the origin of the Main Belt Comets (MBCs) 7968 Elst-Pizzaro, 118401, and P/2005 U1, the dynamics of these three icy asteroids and a large number of hypothetical MBCs were studied. Results of extensive numerical…

The distributions of size and chemical composition in the regolith on airless bodies provides clues to the evolution of the solar system. Recently, the regolith on asteroid (25143) Itokawa, visited by the JAXA Hayabusa spacecraft, was…

We investigate the formation and evolution of "primordial" dusty rings occurring in the inner regions of protoplanetary discs, with the help of long-term, coupled dust-gas, magnetohydrodynamic simulations. The simulations are global and…

The rotational distribution of asteroids as a function of their size is used {as a diagnostic of} their physical properties and evolution. Recent photometric surveys from the Gaia mission, allowing observation of asteroids with long spin…

The surfaces of many planetary bodies, including asteroids and small moons, are covered with dust to pebble-sized regolith held weakly to the surface by gravity and contact forces. Understanding the reaction of regolith to an external…