Results 201 to 210 of about 2,536 (230)

Origin and Evolution of the Long-Period Comets

Earth, Moon, and Planets, 1996
We consider the changes of cometary perihelion distances as a process of diffusion in the value of q, due to perturbations by stars. We find more comets at large q values than is observed. This suggests that a large number of long-period comets is not observed.
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Long-Period Comets and the Oort Cloud

Earth, Moon, and Planets, 2000
Long-period (LP) comets, Halley-type (HT) comets, and even some comets of the Jupiter family, probably come from the Oort cloud, a huge reservoir of icy bodies that surrounds the solar system. Therefore, these comets become important probes to learn about the distant Oort cloud population.
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Distribution of the Aphelia of Long-Period Comets

Publications of the Astronomical Society of Japan, 1976
Abstract By examining the distribution of aphelia of all the comets observed since 1800, we find that the aphelia of long-period comets show a remarkable concentration near the antapex of the solar motion. Some possible interpretations of this phenomenon are discussed in connection with the origin of long-period comets.
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Long‐period Comets and the Oort Cloud

Annals of the New York Academy of Sciences, 1997
ABSTRACT: The long‐period comets pose a unique problem for the impact hazard problem. Because of their very long orbital periods and generally large distances from the Sun, they cannot be surveyed and catalogued in the same manner as the near‐Earth asteroids and short‐period comets. They appear at random, uniformly distributed on the celestial sphere.
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Why Halley-Types Resonate but Long-Period Comets Don't: A Dynamical Distinction between Short- and Long-Period Comets☆

Icarus, 1997
Abstract Several recent studies have noted that the orbital evolution of many comets is influenced by mean-motion resonances with Jupiter. However, the distribution and relative importance of these resonances and the orbital characteristics of the comets affected have not been addressed to date.
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Distribution of long-period comets in perihelion distance

International Astronomical Union Colloquium, 1999
AbstractDistribution of long-period comets in perihelion distance is investigated. The relationN( > q)=C qαseems to be a good approximation to the reality −N(>q)is the number of long-period comets with perihelion distance greater than the valueq( in AU). The complete group of long-period comets is characterized by the valueα =4/3, however,
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The Shortage of Long-Period Comets in Elliptical Orbits

Symposium - International Astronomical Union, 1979
Based on the number of ‘new’ comets seen on near-parabolic orbits, one can predict the number of comets that should be found on definitely elliptical orbits on their subsequent returns. We show here that about three out of four of these returning comets are not observed.
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The activity pattern of distant long period comets

Modern sky surveys now regularly discover comets at distances between 5 and 10 au, or even further, from the Sun. This is expected to become more common when the Vera C Rubin observatory’s Legacy Survey of Space and Time (LSST) begins in around a year. Yet the distant activity of comets is still poorly understood – at such distances
Colin Snodgrass, Carrie Holt
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Planetary impact probabilities for long-period comets

Icarus, 1984
Abstract Planetary impact probabilities for long-period (near-parabolic) comets are determined by averaging Opik's equations over inclination and perihelion distance for each planet. These averaged values compare well with the results of more elaborate Monte Carlo calculations. The impact probabilities are proportional to the square of the normalized
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Some properties of the distribution of long period comets.

2015
The scope of the present study is to compare the flux of observable long period comets obtained numerically to the observed flux of long period comets. Such comparison should give us some hint about the incompleteness of the observed flux with respect to the perihelion distances, the validity of the injection scenario toward the observability, and to ...
Fouchard, Marc, Rickman, Hans, Valsecchi, Giovanni B., Froeschlé, Christiane   +3 more
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