Related papers: Cometary diversity and cometary families
This text was originally written to accompany a series of lectures that I gave at the `35th Saas-Fee advanced course' in Switzerland and at the Institute for Astronomy of the University of Hawaii. It reviews my current understanding of the…
Comets provide a valuable window into the chemical and physical conditions at the time of their formation in the young solar system. We seek insights into where and when these objects formed by comparing the range of abundances observed for…
As comets journey into the inner solar system, they deliver particulates and volatile gases into their comae that reveal the most primitive materials in the solar system. Cometary dust particles provide crucial information for assessing the…
A new classification scheme is introduced for comet-like bodies in the Solar system. It covers the traditional comets as well as the Centaurs and Edgeworth-Kuiper belt objects. At low inclinations, close encounters with planets often result…
Remote investigations of the ancient solar system matter has been traditionally carried out through the observations of long-period (LP) comets that are less affected by solar irradiation than the short-period counterparts orbiting much…
The apparent source region (or regions) of long-period comets as well as the definition of the dynamically new comet are still open questions.The aim of this investigation is to look for the apparent source of selected long period comets…
Exocomets are small bodies releasing gas and dust which orbit stars other than the Sun. Their existence was first inferred from the detection of variable absorption features in stellar spectra in the late 1980s using spectroscopy. More…
The study of comets affords a unique window into the birth, infancy, and subsequent history of the solar system. There is strong evidence that comets incorporated pristine interstellar material as well as processed nebular matter, providing…
Questions regarding how primordial or pristine the comets of the solar system are have been an ongoing controversy. In this review, we describe comets' physical evolution from dust and ice grains in the solar nebula to the contemporary…
Most stars form in dense stellar environments, where frequent close encounters can strongly perturb and reshape the early architecture of planetary systems. The solar system, with its rich population of distant comets, provides a natural…
Past and future dynamical evolution of all 64 long period comets having 1/aori< 1\times10-4 au-1 and qosc > 3.0 au and discovered after 1970 is studied. For all of them we obtained a new, homogeneous set of osculating orbits, including 15…
Comets have been invoked in numerous studies as a potentially important source of dust and gas around stars, but none has studied the thermo-physical evolution, out-gassing rate, and dust ejection of these objects in such stellar systems.…
Molecular oxygen has been confirmed as the fourth most abundant molecule in cometary material O$_2$/H$_2$O $\sim 4$ %) and is thought to have a primordial nature, i.e., coming from the interstellar cloud from which our solar system was…
Comets in the Oort cloud evolve under the influence of internal and external perturbations, such as giant planets, stellar passages, and the galactic tidal field. We aim to study the dynamical evolution of the comets in the Oort cloud,…
Equation of motion for a comet in the Oort cloud is numerically solved. Orbital evolution of the comet under the action of the gravity of the Sun and the Galaxy is presented for various initial conditions. Oscillations of the Sun with…
The solar system's Oort cloud can be perturbed by the Galactic tide and by individual passing stars. These perturbations can inject Oort cloud objects into the inner parts of the solar system, where they may be observed as the long-period…
We measured organic volatiles (CH4, CH3OH, C2H6, H2CO), CO, and water in comet 8P/Tuttle, a comet from the Oort cloud reservoir now in a short-period Halley-type orbit. We compare its composition with two other comets in Halley-type orbits,…
The Oort cloud is usually thought of as a collection of icy comets inhabiting the outer reaches of the Solar system, but this picture is incomplete. We use simulations of the formation of the Oort cloud to show that ~4% of the small bodies…
Cometary dust particles are best preserved remnants of the matter present at the onset of the formation of the Solar System. Space missions, telescopic observations and laboratory analyses advanced the knowledge on the properties of…
The long-term dynamics of Oort cloud comets are studied under the influence of both the radial and the vertical components of the Galactic tidal field. Sporadic dynamical perturbation processes are ignored, such as passing stars, since we…