相关论文: 'Oumuamua as a Cometary Fractal Aggregate: the "Du…
The Sun and >15 percent of nearby stars are surrounded by dusty debris disks that must be collisionally replenished by asteroids and comets, as the dust would otherwise be depleted on <10 Myr timescales (ref. 1). Theoretical studies show…
The presence of dust in the intracluster medium (ICM) has been a long-standing problem that is still awaiting elucidation. Direct observational diagnostics are rather challenging (though not impossible) either because of a sparse…
We study the dynamical properties of objects in hyperbolic orbits passing through the inner Solar system in the context of two different potential sources: interstellar space and the Oort cloud. We analytically derive the probability…
The question of what triggered the nongravitational acceleration of 1I/`Oumuamua continues to attract researchers' attention. The absence of any signs of activity notwithstanding, the prevailing notion is that the acceleration of the…
Planet formation begins with collisional growth of small planetesimals accumulating into larger ones. Such growth occurs while planetesimals are embedded in a gaseous protoplanetary disc. However, small-planetesimals experience collisions…
Recent observations of HL Tau revealed remarkably detailed structure within the system's circumstellar disc. A range of hypotheses have been proposed to explain the morphology, including, e.g., planet-disc interactions, condensation fronts,…
The first definitely interstellar object 1I/'Oumuamua (previously A/2017 U1) observed in our solar system provides the opportunity to directly study material from other star systems. Can such objects be intercepted? The challenge of…
We report the finding of a new, local diffusion instability in a protoplanetary disk, which can operate in a dust fluid, subject to mass diffusion, shear viscosity, and dust-gas drag, provided diffusivity, viscosity, or both decrease…
Planetary debris disks around other stars are analogous to the Asteroid and Kuiper belts in the Solar System. Their structure reveals the configuration of small bodies and provides hints for the presence of planets. The nearby star…
The sticking of micron sized dust particles due to surface forces in circumstellar disks is the first stage in the production of asteroids and planets. The key ingredients that drive this process are the relative velocity between the dust…
Interstellar dust links the formation of the first stars to the rocky planet we inhabit by playing a pivotal role in the cooling and fragmentation of molecular clouds, and catalyzing the formation of water and organic molecules. Despite its…
The possibility that the stellar initial mass function (IMF) arises mostly from cloud structure is investigated with fractal Brownian motion (fBm) clouds that have power-law power spectra. An fBm cloud with a realistic projected power…
This study investigates the origin of interplanetary dust particles (IDPs) through the optical properties, albedo and spectral gradient, of zodiacal light. The optical properties were compared with those of potential parent bodies in the…
Our current understanding of interstellar dust is summarized at an introductory level. Submicron-sized interstellar dust grains absorb and scatter light, and reradiate the absorbed energy in the infrared. The grain population spans a range…
Relatively large dust grains (referred to as pebbles) accumulate at the outer edge of the gap induced by a planet in a protoplanetary disk, and a ring structure with a high dust-to-gas ratio can be formed. Such a ring has been thought to be…
Interplanetary dust particles (IDPs) are an important constituent of the earth's stratosphere, interstellar and interplanetary medium, cometary comae and tails, etc. Their physical and optical characteristics are significantly influenced by…
The detection of Interstellar Objects passing through the Solar System offers the promise of constraining the physical and chemical processes involved in planetary formation in other extrasolar systems. While the effect of outgassing by…
(Abridged) We present CARMA observations of the thermal dust emission from the circumstellar disks around the young stars RYTau and DGTau at wavelengths of 1.3mm and 2.8mm. The angular resolution of the maps is as high as 0.15arcsec, or…
Rapid orbital drift of macroscopic dust particles is one of the major obstacles against planetesimal formation in protoplanetary disks. We reexamine this problem by considering porosity evolution of dust aggregates. We apply a porosity…
The first interstellar objects, 1I/`Oumuamua, 2I/Borisov and 3I/ATLAS, were discovered over the past decade. We follow the trajectories of known interstellar objects in the gravitational potential of the Milky Way galaxy to constrain their…