scholarly journals Orbital evolution of short-period comets with high values of the Tisserand constant

2006 ◽  
Vol 2 (S236) ◽  
pp. 35-42 ◽  
Author(s):  
N.Yu. Emel'yanenko
Keyword(s):  
Dynamical Evolution ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Time Interval ◽  
Short Period

AbstractThe orbital evolution of comets with high values of the Tisserand constant is studied for a time interval of 800 years. Scenarios of dynamical evolution are obtained for 85 comets. Particular features of the orbital evolution of the comets of this class are singled out. The orbits of all comets are tangent to the orbit of Jupiter and have a steadily low inclination. For 80% of comets, the evolution scenario includes a timespan in which the comets move in low-eccentricity orbits. The possibility is analyzed of a change in the Tisserand constant and of a transition of the comet to be controlled by other giant planets.

scholarly journals The diverse origin of exoplanets' eccentricities & inclinations

2010 ◽  
Vol 6 (S276) ◽  
pp. 221-224
Author(s):  
Eric B. Ford
Keyword(s):  
Rotation Axis ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Direct Imaging ◽  
Wide Binary ◽  
Hot Jupiters ◽  
Short Period ◽  
New Type ◽  
Low Mass ◽  
Diverse Origin

AbstractRadial velocity surveys have discovered over 400 exoplanets. While measuring eccentricities of low-mass planets remains a challenge, giant exoplanets display a broad range of orbital eccentricities. Recently, spectroscopic measurements during transit have demonstrated that the short-period giant planets (“hot-Jupiters”) also display a broad range of orbital inclinations (relative to the rotation axis of the host star). Both properties pose a challenge for simple disk migration models and suggest that late-stage orbital evolution can play an important role in determining the final architecture of planetary systems. One possible formation mechanism for the inclined hot-Jupiters is some form of eccentricity excitation (e.g., planet scattering, secular perturbations due to a distant planet or wide binary) followed tidal circularization. The planet scattering hypothesis also makes predictions for the population of planets at large separations. Recent discoveries of planets on wide orbits via direct imaging and highly anticipated results from upcoming direct imaging campaigns are poised to provide a new type of constraint on planet formation. This proceedings describes recent progress in understanding the formation of giant exoplanets.

scholarly journals The Evolution of Jupiter Family Comets over 2000 Years

1992 ◽  
Vol 152 ◽  
pp. 269-274 ◽  
Author(s):  
G. Tancredi ◽  
H. Rickman
Keyword(s):  
Data Base ◽  
Orbital Evolution ◽  
Physical Parameters ◽  
Time Interval ◽  
Orbital Elements ◽  
Present Epoch ◽  
Numerical Integrations ◽  
Short Period

The orbital evolution of the whole sample sample of short-period comets was computed by numerical integrations for a time interval of 2000 yr centered on the present epoch. This data base is intended to serve in various studies involving the statistics of orbital evolution and correlation with physical parameters or discovery circumstances. We present some results concerning the following aspects: the evolution of the orbital elements and their past-future asymmetry, statistics on the discovery of comets and on the encounters of comets with Jupiter.

scholarly journals Statistical and numerical studies of the orbital evolution of short-period comets

1985 ◽  
Vol 83 ◽  
pp. 261-278
Author(s):  
A. Carusi ◽  
G.B. Valsecchi
Keyword(s):  
Dynamical Evolution ◽  
Orbital Evolution ◽  
Special Role ◽  
Outer Solar System ◽  
Orbital Elements ◽  
Numerical Work ◽  
Numerical Studies ◽  
Short Period ◽  
Evolutionary Paths ◽  
Work Done

AbstractThe evolutionary paths connecting cometary reservoirs in the outer solar system and the population of periodic comets involve stellar and planetary perturbations. Close planetary encounters play a special role, making the dynamical evolution slow or fast depending on the orbital elements of the comet at various stages of the process. In this paper numerical work done in the last decades on this subject, using both real and fictitious objects, is reviewed.

scholarly journals Orbital decay of short-period gas giants under evolving tides

2019 ◽  
Vol 486 (3) ◽  
pp. 3963-3974 ◽  
Author(s):  
Jaime A Alvarado-Montes ◽  
Carolina García-Carmona
Keyword(s):  
Extreme Case ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Tidal Interactions ◽  
Extrasolar Systems ◽  
Orbital Decay ◽  
Short Period ◽  
Order Of Magnitude ◽  
Formation And Evolution ◽  
Host Stars

Abstract The discovery of many giant planets in close-in orbits and the effect of planetary and stellar tides in their subsequent orbital decay have been extensively studied in the context of planetary formation and evolution theories. Planets orbiting close to their host stars undergo close encounters, atmospheric photoevaporation, orbital evolution, and tidal interactions. In many of these theoretical studies, it is assumed that the interior properties of gas giants remain static during orbital evolution. Here, we present a model that allows for changes in the planetary radius as well as variations in the planetary and stellar dissipation parameters, caused by the planet’s contraction and change of rotational rates from the strong tidal fields. In this semi-analytical model, giant planets experience a much slower tidal-induced circularization compared to models that do not consider these instantaneous changes. We predict that the eccentricity damping time-scale increases about an order of magnitude in the most extreme case for too inflated planets, large eccentricities, and when the planet’s tidal properties are calculated according to its interior structural composition. This finding potentially has significant implications on interpreting the period–eccentricity distribution of known giant planets as it may naturally explain the large number of non-circularized, close period currently known. Additionally, this work may help to constrain some models of planetary interiors, and contribute to a better insight about how tides affect the orbital evolution of extrasolar systems.

scholarly journals Probing the impact of stellar duplicity on the frequency of giant planets: Final results of our VLT/NACO survey

2010 ◽  
Vol 6 (S276) ◽  
pp. 409-410 ◽  
Author(s):  
Anne Eggenberger ◽  
Stéphane Udry ◽  
Gaël Chauvin ◽  
Thierry Forveille ◽  
Jean-Luc Beuzit ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Proper Motion ◽  
Binary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
The Other ◽  
Physical Association ◽  
Short Period ◽  
Solar Type ◽  
The Impact

AbstractIf it is commonly agreed that the presence of a (moderately) close stellar companion affects the formation and the dynamical evolution of giant planets, the frequency of giant planets residing in binary systems separated by less than 100 AU is unknown. To address this issue, we have conducted with VLT/NACO a systematic adaptive optics search for moderately close stellar companions to 130 nearby solar-type stars. According to the data from Doppler surveys, half of our targets host at least one planetary companion, while the other half show no evidence for short-period giant planets. We present here the final results of our survey, which include a new series of second-epoch measurements to test for common proper motion. The new observations confirm the physical association of two companion candidates and prove the unbound status of many others. These results strengthen our former conclusion that circumstellar giant planets are slightly less frequent in binaries with mean semimajor axes between 35 and 100 AU than in wider systems or around single stars.

scholarly journals Planetary Formation in Protostellar Disks

1997 ◽  
Vol 163 ◽  
pp. 321-330 ◽  
Author(s):  
D.N.C. Lin
Keyword(s):  
Convection Zone ◽  
Solar Nebula ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Minor Planets ◽  
Stellar Convection ◽  
Short Period ◽  
Present Distribution ◽  
Large Eccentricity

AbstractRecent discoveries of planets around other stars suggest that planets are ubiquitous and their dynamical properties are diverse. We reviewed the formation mechanism for protoplanets and the post-formation planet-disk tidal interaction which may have led the short-period planets to their present configuration. We suggest that these planets may be the survivors of a populations of similar planets which have plunged into and contaminated the stellar convection zone. In the context of the solar system, the mass of the giant planets and the present distribution of the minor planets may be used to infer the structure and evolution for the primordial solar nebula. The large eccentricity of 70 Vir and HD 114762 may be due to cohesive collisions in planetary systems which become unstable during their long term orbital evolution.

scholarly journals The Short-Period Binary Frequency Among Low-Mass Pre-Main Sequence Stars

1992 ◽  
Vol 135 ◽  
pp. 30-40
Author(s):  
Robert D. Mathieu
Keyword(s):  
Star Formation ◽  
Formation Process ◽  
Main Sequence ◽  
Early Period ◽  
Dynamical Evolution ◽  
Orbital Evolution ◽  
Semi Major Axis ◽  
Single Star ◽  
Binary Formation ◽  
Short Period

The pre-main sequence (PMS) binary frequency is a fundamental datum in the study of binary formation. It reflects on numerous basic issues, such as:• The formation process. Binary stars are the primary branch of the star-formation process, and thus their frequency is an essential challenge to star-formation theories. (Indeed, the infrequency of single-star formation is likely as significant as the binary frequency.)• The epoch of binary formation. Assessing whether the binary population exists in total by the pre-main sequence phase sets an upper limit on the binary formation timescale.• Early period evolution. The frequency distribution as a function of period of PMS binaries, when compared to the distribution at the zero-age main sequence, can shed light on early orbital evolution.• The interaction of binaries with disks. The formation and consequent dynamical evolution of a binary with semi-major axis less than typical disk radii must substantially modify disk structures and accretion flows. Thus the binary frequency might differ between PMS stars with and without associated disks.

scholarly journals Dynamical evolution of near-Sun objects

2014 ◽  
Vol 9 (S310) ◽  
pp. 126-129
Author(s):  
Vacheslav V. Emel'yanenko ◽  
Mikhail A. Shelyakov
Keyword(s):  
Dynamical Evolution ◽  
Orbital Evolution ◽  
The Other ◽  
Secular Perturbations ◽  
The Past ◽  
Other Hand ◽  
Short Period ◽  
Near Earth Objects

AbstractThe dynamical evolution of short-period objects having perihelia at small heliocentric distances is discussed. We have investigated the motion of multiple-apparition members of the Marsden and Kracht sungrazing groups. The orbital evolution of these objects on timescales < 10 Kyr is mainly determined by the Kozai-Lidov secular perturbations. These objects are dynamically connected with high-inclination near-Earth objects. On the other hand, we have found several observed near-Earth objects that evolve in the same way, reaching small perihelion distances on short timescales in the past.

scholarly journals Origin of the dusty disks around white dwarfs

2007 ◽  
Vol 3 (S249) ◽  
pp. 381-384
Author(s):  
R. B. Dong ◽  
Y. Wang ◽  
D. N. C. Lin ◽  
X. W. Liu
Keyword(s):  
Total Mass ◽  
Main Sequence ◽  
Dynamical Evolution ◽  
Central Star ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Mean Motion Resonances ◽  
Host Stars ◽  
Dusty Disks ◽  
Dust Ring

AbstractSome circumstantial evidence for residual planetesimals is constructed based on the recent discovery of a dusty ring around a young white dwarf at the center of the Helix nebula (Suet al. 2007). This ring extends between about 35 and 150 AU from the nebula center, and have a total mass of about 0.13M⊕. In this paper we propose that this ring is the by-product of planets and planetesimals' orbital evolution during the epoch when the central star rapidly lost most of its mass. We examine the dynamical evolution of planetary systems similar to the solar system (i.e. with gas giant planets and residual planetesimals) as their host stars evolve off the main sequence. During the process, some planetesimals will be captured by the gas giants into mean motion resonances and their mutual collisions will form a dust ring similar to that observed at the center of the Helix nebula.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods &lt; 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq &lt;2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods &lt; 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

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