Related papers: Origin of 1I/'Oumuamua. I. An ejected protoplaneta…
Our goal is to understand primary accretion of the first planetesimals. The primitive meteorite record suggests that sizeable planetesimals formed in the asteroid belt over a period longer than a million years, each composed entirely of an…
We investigate the possibility to find evidence for planets in circumstellar disks by infrared and submillimeter interferometry. We present simulations of a circumstellar disk around a solar-type star with an embedded planet of 1 Jupiter…
We present a comprehensive study of disks around 81 young low-mass stars and brown dwarfs in the nearby ~2-Myr-old Chamaeleon I star-forming region. We use mid-infrared photometry from the Spitzer Space Telescope, supplemented by findings…
Gaseous circumbinary disks (CBDs) that are highly inclined to the binary orbit are commonly observed in nature. These disks harbor particles that can reach large mutual inclinations as a result of nodal precession once the gas disk has…
A planetary system can undergo multiple episodes of intense dynamical activities throughout its life, resulting in the production of star-grazing planetesimals (or exocomets) and pollution of the host star. Such activity is especially…
Among the outer solar system minor planet orbits there is an observed gap in perihelion between roughly 50 and 65 au at eccentricities $e\gtrsim0.65$. Through a suite of observational simulations, we show that the gap arises from two…
Several hundred stars older than 10 million years have been observed to have infrared excesses. These observations are explained by dust grains formed by the collisional fragmentation of hidden planetesimals. Such dusty planetesimal discs…
The Milky way Galaxy is brimming with free-floating objects, including stars, planets and planetesimals. For the purpose of this chapter, we define a free-floating object as a solid body that is not orbited by a considerably more massive…
We performed single point [C I] $^3$P$_1$-$^3$P$_0$ and CO J=4-3 observations toward three T Tauri stars, DM Tau, LkCa 15, and TW Hya, using the Atacama Large Millimeter/submillimeter Array (ALMA) Band 8 qualification model receiver…
Meteoroids originating from the local interstellar medium, traverse the solar system. This has been proven by in situ measurements by interplanetary spacecraft as well as highly sensitive radar measurements. Early attempts to detect…
The wavelength dependences of interstellar extinction and polarization, supplemented by observed elemental abundances and the spectrum of infrared emission from dust heated by starlight, strongly constrain dust models. One dust model that…
We modeled the trajectories of material ejected from 20 nearby debris disk stars, including Epsilon Eridani (Ran), Vega, Fomalhaut, and Beta Pictoris, within a simulated Milky Way potential in order to quantify their contribution to the…
Comet 2I/Borisov is the first true interstellar comet discovered. Here we present results from observational programs at two Indian observatories, 2 m Himalayan Chandra Telescope at the Indian Astronomical Observatory, Hanle (HCT) and 1.2 m…
Observations of protoplanetary disks provide information on planet formation and the reasons for the diversity of planetary systems. The key to understanding planet formation is the study of dust evolution from small grains to pebbles.…
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…
The formation of planetesimals is expected to occur via particle-gas instabilities that concentrate dust into self-gravitating clumps. Triggering these instabilities requires the prior pileup of dust in the protoplanetary disk. Until now,…
Planets are a natural byproduct of the stellar formation process, resulting from local aggregations of material within the disks surrounding young stars. Whereas signatures of gas-giant planets at large orbital separations have been…
Dust in debris disks is generated by collisions among planetesimals. The existence of these planetesimals is a consequence of the planet formation process, but the relationship between debris disks and planets has not been clearly…
We investigate the possibility to find evidence for planets in circumstellar disks by infrared and submillimeter interferometry. Hydrodynamical simulations of a circumstellar disk around a solar-type star with an embedded planet of 1…
[abridged] Protoplanetary disks with AU-scale inner clearings, often referred to as transitional disks, provide a unique sample for understanding disk dissipation mechanisms and possible connections to planet formation. Observations of…