Long-period comet flux in the planetary region: Dynamical evolution from the Oort cloud

AbstractThe dynamical evolution of 2⋅105 hypothetical Oort cloud comets by the action of planetary, galactic and stellar perturbations during 2⋅109 years is studied numerically. The evolution of comet orbits from the outer (104 AU <a<5⋅104 AU, a is semimajor axes) and the inner Oort cloud (5⋅103 AU <a<104 AU) to near-Earth space is investigated separately. The distribution of the perihelion (q) passage frequency in the planetary region is obtained calculating the numbers of comets in every interval of Δ q per year. The flux of long-period (LP) comets (orbital periods P>200 yr) with perihelion distances q<1.5 AU brighter than visual absolute magnitude H10=7 is ∼ 1.5 comets per year, and ∼18 comets with H10<10.9. The ratio of all LP comets with q<1.5 AU to ‘new’ comets is ∼5. The frequency of passages of LP comets from the inner Oort cloud through region q<1.5 AU is ∼3.5⋅10−13 yr−1, that is roughly one order of magnitude less than frequency of passages of LP comets from the outer cloud (∼5.28⋅10−12 yr−1). We show that the flux of ‘new’ comets with 15<q<31 AU is higher than with q<15 AU, by a factor ∼1.7 for comets from the outer Oort cloud and, by a factor ∼7 for comets from the inner cloud. The perihelia of comets from the outer cloud previously passed through the planetary region are predominated in the Saturn-Uranus region. The majority of inner cloud comets come in the outer solar system (q>15 AU), and a small fraction (∼0.01) of them can reach orbits with q<1.5 AU. The frequency of transfer of comets from the inner cloud (a<104 AU) to the outer Oort cloud (a>104 AU), from where they are injected to the region q<1.5 AU, is ∼6⋅10−14 yr−1.

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Long-period comet C/1963 A1 (Ikeya), the probable parent body of π-Hydrids, δ-Corvids, November α-Sextantids, and ϑ-Leonids

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936407 ◽

2019 ◽

Vol 631 ◽

pp. A112 ◽

Cited By ~ 1

Author(s):

L. Neslušan ◽

M. Hajduková

Keyword(s):

Dynamical Evolution ◽

Parent Body ◽

Video Data ◽

Surveillance Video ◽

Evolutionary Time ◽

Meteoroid Stream ◽

Long Period ◽

The Mean ◽

Meteor Data ◽

Period Comet

Aims. We study the meteoroid stream of the long-period comet C/1963 A1 (Ikeya) to predict the meteor showers originating in this comet. We also aim to identify the predicted showers with their real counterparts. Methods. We modeled 23 parts of a theoretical meteoroid stream of the parent comet considered. Each of our models is characterized by a single value of the evolutionary time and a single value of the strength of the Poynting–Robertson effect. The evolutionary time is defined as the time before the present when the stream is modeled and when we start to follow its dynamical evolution. This period ranges from 10 000 to 80 000 yr. In each model, we considered a stream consisting of 10 000 test particles that dynamically evolve, and their dynamics is followed via a numerical integration up to the present. At the end of the integration, we analyzed the mean orbital characteristics of particles in the orbits approaching Earth’s orbit, which thus enabled us to predict a shower related to the parent comet. We attempted to identify each predicted shower with a shower recorded in the International Astronomical Union Meteor Data Center list of all showers. In addition, we tried to separate, often successfully, a real counterpart of each predicted shower from the databases of real meteors. Results. Many modeled parts of the stream of comet C/1963 A1 are identified with the corresponding real showers in three video-meteor databases. No real counterpart is found in the IAU MDC photographic or radio-meteor data. Specifically, we predict five showers related to C/1963 A1. Two predicted showers are identified with π-Hydrids #101 and δ-Corvids #729. The third predicted shower is only vaguely similar to November α-Sextantids #483, when its mean orbit is compared with the mean orbit of the November α-Sextantids in the IAU MDC list of all showers. However, the prediction is very consistent with the corresponding showers newly separated from three video databases. Another predicted shower has no counterpart in the IAU MDC list, but there is a good match of the prediction and a shower that we separated from the Cameras for Allsky Meteor Surveillance video data. We name this new shower ϑ-Leonids. The last of the predicted showers should be relatively low in number and, hence, no real counterparts were either found in the IAU MDC list or separated from any considered database.

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Physical and Dynamical Evolution of Long-Period Comets

Symposium - International Astronomical Union ◽

10.1017/s0074180900012869 ◽

1979 ◽

Vol 81 ◽

pp. 277-282 ◽

Cited By ~ 3

Author(s):

Paul R. Weissman

Keyword(s):

Solar System ◽

Dynamical Evolution ◽

Oort Cloud ◽

Observational Evidence ◽

General Shape ◽

Long Period ◽

Spherical Cloud ◽

Large Spike ◽

Large Spherical

Oort (1950) first suggested that the source of the long-period comets is a large spherical cloud of comets surrounding the solar system and extending roughly halfway to the nearest stars. The observational evidence for this is the distribution of original inverse semi-major axes of the long-period comets which shows a large spike of comets at very small positive values of 1/ao, less than 10−4 AU−1. Attempts to model the evolution of these comets by Oort in his original paper, by Kendall (1961), Shteins (1961), and Whipple (1962) were successful in recreating the general shape of the 1/ao distribution. However in each case the authors were unable to match the observed ratio of new comets from the Oort cloud versus older comets evolving under the influence of planetary perturbations.

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C/2010 U3 (Boattini): A Bizarre Comet Active at Record Heliocentric Distance

10.5194/epsc2021-638 ◽

2021 ◽

Author(s):

Man-To Hui ◽

Davide Farnocchia ◽

Marco Micheli

Keyword(s):

Heliocentric Distance ◽

Solar Radiation Pressure ◽

Oort Cloud ◽

Pressure Force ◽

Water Ice ◽

Cometary Dust ◽

Long Period ◽

Subsolar Point ◽

Radiation Pressure Force ◽

Period Comet

We report an identification of long-period comet C/2010 U3 (Boattini) active at a new record inbound heliocentric distance of rH &#8776; 26 au. Two outburst events around 2009 and 2017 were observed. The dust morphology of the coma and tail cannot be explained unless the Lorentz force, solar gravitation, and solar radiation pressure force are all taken into account. Optically dominant dust grains have radii of ~10 &#956;m and are ejected protractedly at speeds &#8804;50 m s&#8722;1 near the subsolar point. The prolonged activity indicates that sublimation of supervolatiles (e.g., CO, CO2) is at play. Similar to other long-period comets, the colour of the cometary dust is redder than the solar colours. We also observed potential colour variations when the comet was at 10 < rH < 15 au, concurrent with the onset of crystallisation of amorphous water ice, if any. Using publicly available and our refined astrometric measurements, we estimated the precise trajectory of the comet, propagated it backward to its previous perihelion, and found that the comet visited the planetary region ~2 Myr ago at perihelion distance q &#8776; 8 au. Thus, C/2010 U3 (Boattini) is almost certainly a dynamically old comet from the Oort cloud, and the observed activity cannot be caused by retained heat from the previous apparition. The detailed study is presented in Hui et al. (2019, AJ, 157, 162).

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2006 SQ372: A LIKELY LONG-PERIOD COMET FROM THE INNER OORT CLOUD

The Astrophysical Journal ◽

10.1088/0004-637x/695/1/268 ◽

2009 ◽

Vol 695 (1) ◽

pp. 268-275 ◽

Cited By ~ 21

Author(s):

Nathan A. Kaib ◽

Andrew C. Becker ◽

R. Lynne Jones ◽

Andrew W. Puckett ◽

Dmitry Bizyaev ◽

...

Keyword(s):

Oort Cloud ◽

Long Period ◽

Period Comet

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The problem of the 1/a-distribution and cometary fading

International Astronomical Union Colloquium ◽

10.1017/s0252921100084001 ◽

1985 ◽

Vol 83 ◽

pp. 311-317

Author(s):

M.E. Bailey

Keyword(s):

Steady State ◽

Ad Hoc ◽

Cloud Model ◽

Oort Cloud ◽

Comet Nucleus ◽

Long Period ◽

The Mean ◽

Viable Model ◽

Perihelion Passage ◽

Period Comet

AbstractThe background to the problem of explaining the frequency distribution of cometary 1/a-values is briefly reviewed and it is emphasised that the explanation in terms of the Oort Cloud model relies on an ad hoc fitting function - the fading/disruption probability per revolution. Assuming an underlying steady-state Oort Cloud and the integral equation formalism developed by Oort and Yabushita to predict the 1/a-distribution for an arbitrary fading probability, we have been able to constrain the unknown fading function by comparison with observations. In agreement with previous work we find that the tendency for fading or disruption should be strong at small 1/a-values and weak at large 1/a-values. The mean fading probability per revolution, k(x), is found to lie within a factor roughly of order 2 about k(x) ≈ 0.3(1+(x/4 × 10−3)2)−3/2, where × is 1/a in units AU−1. A physical model for fading which might qualitatively account for this behaviour is tentatively proposed. This depends on the thermal shock experienced by a long-period comet nucleus around perihelion passage. It is emphasised that until a viable model for fading has been found, the validity of the steady-state primordial hypothesis remains unresolved.

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From the Oort cloud to Halley-type comets

International Astronomical Union Colloquium ◽

10.1017/s0252921100031638 ◽

1999 ◽

Vol 173 ◽

pp. 327-338 ◽

Cited By ~ 5

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 < 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 <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 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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Galactic tide and local stellar perturbations on the Oort cloud: creation of interstellar comets

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935330 ◽

2019 ◽

Vol 629 ◽

pp. A139 ◽

Cited By ~ 9

Author(s):

S. Torres ◽

M. X. Cai ◽

A. G. A. Brown ◽

S. P. Zwart

Keyword(s):

Dynamical Evolution ◽

Cumulative Effect ◽

Oort Cloud ◽

Radial Velocities ◽

Current Status ◽

Interstellar Space ◽

The Sun ◽

Semi Major Axis ◽

Software Environment ◽

External Perturbations

Comets in the Oort cloud evolve under the influence of internal and external perturbations, such as giant planets, stellar passages, and the Galactic gravitational tidal field. We aim to study the dynamical evolution of the comets in the Oort cloud, accounting for the perturbation of the Galactic tidal field and passing stars. We base our study on three main approaches; analytic, observational, and numerical. We first construct an analytical model of stellar encounters. We find that individual perturbations do not modify the dynamics of the comets in the cloud unless very close (<0.5 pc) encounters occur. Using proper motions, parallaxes, and radial velocities from Gaia DR2 and combining them with the radial velocities from other surveys, we then construct an astrometric catalogue of the 14 659 stars that are within 50 pc of the Sun. For all these stars we calculate the time and distance of closest approach to the Sun. We find that the cumulative effect of relatively distant (≤1 pc) passing stars can perturb the comets in the Oort cloud. Finally, we study the dynamical evolution of the comets in the Oort cloud under the influence of multiple stellar encounters from stars that pass within 2.5 pc of the Sun and the Galactic tidal field over ±10 Myr. We use the Astrophysical Multipurpose Software Environment (AMUSE), and the GPU-accelerated direct N-body code ABIE. We considered two models for the Oort cloud, compact (a ≤ 0.25 pc) and extended (a ≤ 0.5 pc). We find that the cumulative effect of stellar encounters is the major perturber of the Oort cloud for a compact configuration while for the extended configuration the Galactic tidal field is the major perturber. In both cases the cumulative effect of distant stellar encounters together with the Galactic tidal field raises the semi-major axis of ~1.1% of the comets at the edge of the Oort cloud up to interstellar regions (a > 0.5 pc) over the 20 Myr period considered. This leads to the creation of transitional interstellar comets (TICs), which might become interstellar objects due to external perturbations. This raises the question of the formation, evolution, and current status of the Oort cloud as well as the existence of a “cloud” of objects in the interstellar space that might overlap with our Oort cloud, when considering that other planetary systems should undergo similar processes leading to the ejection of comets.

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Beginning of Activity in Long-period Comet C/2015 ER61 (PANSTARRS)

The Astronomical Journal ◽

10.3847/1538-3881/aa63f2 ◽

2017 ◽

Vol 153 (5) ◽

pp. 206 ◽

Cited By ~ 7

Author(s):

Karen J. Meech ◽

Charles A. Schambeau ◽

Kya Sorli ◽

Jan T. Kleyna ◽

Marco Micheli ◽

...

Keyword(s):

Long Period ◽

Period Comet

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On the relationship between long-period comets and large trans-Neptunian planetary bodies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316012692 ◽

2016 ◽

Vol 12 (S325) ◽

pp. 263-265

Author(s):

Rustam Guliyev ◽

Ayyub Guliyev

Keyword(s):

Solar System ◽

Numerical Integration ◽

Dynamical Evolution ◽

Integration Methods ◽

Long Period ◽

Planetary Bodies ◽

Numerical Integration Methods ◽

Relationship Of ◽

The Relationship

AbstractIn the present work we investigate the possible relationship of long-period comets with five large and distant trans-Neptunian bodies (Sedna, Eris, 2007 OR10, 2012 VP113and 2008 ST291) in order to determine the probability of the transfer of a part of these kind of comets to the inner of the Solar System. To identify such relationships, we studied the relative positions of the comet orbits and listed TNOs. Using numerical integration methods, we examined dynamical evolution of the comets and have found one encounter of comet C/1861J1 and Eris.

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