相关论文: Thermal Alteration and Differential Sublimation Ca…
Distant long-period comet C/2017 K2 has been outside the planetary region of the solar system for 3 Myr, negating the possibility that heat retained from the previous perihelion could be responsible for its activity. This inbound comet is…
Sublimative outgassing of comets produces torques that alter the rotation state of their nuclei. Recently, parameterized sublimative torque models have been developed to study rotation state changes of individual comet nuclei and…
Brown dwarfs are essential targets for understanding planetary and sub-stellar atmospheres across a wide range of thermal and chemical conditions. As surveys continue to probe ever deeper, and as observing capabilities continue to improve,…
We used the UltraViolet-Optical Telescope on board Swift to systematically follow the dynamically new comet C/2013 A1 (Siding Spring) on its approach to the Sun. The comet was observed from a heliocentric distance of 4.5 AU pre-perihelion…
We use a quasi 3-D thermal evolution model for a spherical comet nucleus, which takes into account the diurnal and latitudinal variation of the solar flux, but neglects lateral heat conduction. We model the thermal evolution and activity of…
Ice naturally forms in the disordered or ``amorphous'' state when accreted from vapor at temperatures and pressures found in the interstellar medium and in the frigid, low density outer regions of the Sun's protoplanetary disk. It is…
The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA's DESTINY+ target. The rotational lightcurve and spin properties were investigated based on the data…
Asteroids with low orbital perihelion distances experience extreme heating from the Sun that can modify their surfaces and trigger non-typical activity mechanisms. These objects are generally difficult to observe from ground-based…
2009 MS9 is a trans-Neptunian object (TNO) whose perihelion brings it close to the distance where some long period comets are seen to become active. Knowing this, and the fact that this object appears to brighten in excess of it's predicted…
Context. The composition of a protoplanetary disk at a given location does not only depend on temperature and pressure but also on the time dependent transport of matter, such as radial drift of solid bodies, which could release water and…
Aims. We aim to constrain the size and porosity of ejected dust particles from comet 252P/LINEAR and their evolution near the perihelion via near-infrared multiband polarimetry. A close approach of the comet to the Earth in March 2016…
Kuiper belt objects, such as Arrokoth, the probable progenitors of short-period comets, formed and evolved at large heliocentric distances, where the ambient temperatures appear to be sufficiently low for preserving volatile ices. By…
We observed the dynamically similar near-Sun asteroids 2021 PH27 and 2025 GN1 for their optical colors. These objects have the lowest known semi-major axes of any asteroids. 2021 PH27 has the largest general relativistic effects of any…
Potential effects of sublimation of water ice from very slowly moving millimeter-sized and larger grains, a product of activity at ~10 AU or farther from the Sun driven presumably by annealing of amorphous water ice, are investigated by…
Evidence for cometary activity beyond Jupiter and Saturn's orbits -- such as that observed for Centaurs and long period comets -- suggests that the thermal processing of comet nuclei starts long before they enter the inner Solar System,…
We analyze findings of the Stardust mission that brought to the Earth dust from the 81P/Wild 2 coma. Just as the data of the Deep Impact mission to 9P/Tempel 1, they are at odds with the widely accepted condensation/sublimation comet…
Active asteroids show (typically transient) cometary activity, driven by a range of processes. A sub-set, sometimes called main-belt comets, may be driven by sublimation and so could be useful for tracing the present-day distribution of…
Comet--asteroid transition (CAT) objects are small solar system bodies in the process of evolving from cometary nuclei into asteroids, as they gradually lose volatile substances due to solar heating. The volatile material is mainly water…
Our knowledge about the physical processes determining the activity of comets were mainly influenced by several extremely successful space missions, the predictions of theoretical models and the results of laboratory experiments. However,…
A collision between two atomic nuclei accelerated at a speed close to that of light creates a dense system of quarks and gluons. Interactions among them are so strong that they behave collectively like a droplet of fluid of ten-femtometer…