Near-parabolic Comets Main Page

Solar System
Dynamics &
Planetology
Group

SSDP Home Page of Near-Parabolic Comets

We start to construct the Cometary Database consisted of near-parabolic comets.
At these pages the new orbital solutions will be included systematically during the progress of our investigation.

For each comet are given three types of orbits:

Osculating orbital elements with their uncertainties,
Original orbital elements with their uncertainties given at 250 au from the Sun, i.e. before entering the planetary zone,
Future orbital elements with their uncertainties given at 250 au from the Sun, i.e. after leaving the planetary zone.

Example of orbits and other data for an individual comet.
Accompanying materials: residuals and O-C diagrams (see example given above), samples of comets, published papers that include some parts of results presented here.

The method of orbital calculations

The equation of comet's motion are integrated numerically using the reccurent power series method (e.g. Sitarski 1989, Acta Astron. 39, 345, direct links to papers quoted here are in this page) taking into account perturbations by all planets and including the relativistic effects. All orbital calculations are based on the Warsaw numerical ephemeris DE405/WAW of the Solar system, consistent with high accuracy with the JPL ephemeris DE405 (Sitarski, 2002, Acta Astron. 52, pp 471-486)

Original and future orbits

To calculate the original and future orbital elements as well as their uncertainties (taken at 250 au from the Sun where planetary perturbations are negligible) the dynamical calculations for swarms of starting osculating orbits were performed for each comet. Each swarm was constructed according to a Monte Carlo method proposed by Sitarski (1998, Acta Astron. 48, pp 547-561) where the entire swarm fulfil the Gaussian statistics of fitting to positional data used for a given osculating orbit determination (examples are in Królikowska and Dybczyński, 2010, MNRAS 404, 1886). Typically, each swarm consists of 5001 VCs including the nominal orbit; it was checked that this number of orbital clones gives a very sufficient sample for obtaining reliable statistics at 250 au from the Sun. Values of uncertainties of original/future orbital elements (including inverse semimajor axes 1/a) were derived by fitting the distribution of a given orbital element (including 1/a-distribution) of original/future swarm of VCs to Gaussian distribution. All distributions of orbital elements as well as1/a-distributions of analysed comets were still perfectly Gaussian at 250 au from the Sun.

Accuracy of the cometary orbit

In 1978 Marsden, Sekanina, & Everhardt (1978, AJ 83, 64) formulated the recipe to evaluate the accuracy of the osculating cometary orbits obtained from the positional data. Here, however, we used the new recipe of orbital quality assessment introduced by Królikowska & Dybczyński (2013, MNRAS 435, 440) where are discussed reasons why the modification of original MSE recipe was introduced. According to this new scheme the following classes of orbital quality are given (in order from excellent to extremely poor orbit): 1a+, 1a, 1b , 2a, 2b, 3a, 3b, 4.

Samples of near-parabolic comets

Sample A1
This sample consists of 28 near-parabolic comets of q_osc < 3.1 au and 1/a_ori ≤ 100 × 10^-6 au^-1 discovered before the year 2006. Sample A1 is very incomplete and includes about 60 per cent of all discovered LPCs that fulfil the above conditions. Almost all comets (except C/1992 J1 and C/2001 K3) from this sample have non-gravitational (hereafter NG) orbits and these NG solutions characterized by a clear decrease in root-mean-square error (rms) compared with the rms for purely gravitational (hereafter GR) orbits, only C/1974 F1 displays a slight decrease of rms for NG~solution. Most comets from this sample was examined by Królikowska and Dybczyński (2010, MNRAS 404, 1886) and Dybczyński and Królikowska (2011, MNRAS 416, 51).
Sample A2
Complete sample of 22 comets of q_osc < 3.1 au and 1/a_ori ≤ 150 × 10^-6 au^-1 discovered in the period 2006—2010. This sample of comets was examined in Królikowska and Dybczyński (2013, MNRAS 435, pp 440-459) and NG solutions were determined for eleven of them.
Sample B
Almost complete sample of 69 comets of q_osc ≥ 3.1 au and 1/a_ori ≤ 100 × 10^-6 au^-1 discovered in the period 1970--2007; missing three comets were still observed at the beginning of 2013. The dynamical evolution of 59 comets of this sample was examined by Królikowska and Dybczyński (2010, MNRAS 404, 1886) and Dybczyński and Królikowska and (2011, MNRAS 416, 51); twelve comets from the Sample B have NG orbits.
The Warsaw Catalogue of cometary orbits: 119 near-parabolic comets that consists of samples A1, A2 and B (Królikowska M., 2014, A&A 567, A126) ) where also all tables accompanying this publication are given Online; additionally the catalogue is available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A126. Any usage of the data from the samples A1, A2 or B must include this publication as its source.
Sample 1901-1950-PartI
This is Part I of the New Catalogue of One-Apparition Comets discovered in the years 1901—1950 prepared by Królikowska M., Sitarski G., Pittich E.M., Szutowicz S., Ziołkowski K., Rickman H., Gabryszewski R., and Rickman B., 2014, accepted for publication in A&A; includes complete sample of 38 comets of 1/a_ori ≤ 130 × 10^-6 au^-1 (according to Catalogue of Cometary Orbits, Marsden B.G. and Williams G.V., 17th Ed.) discovered in the first half of the twentieth century (orbital quality class 1 and 2).

We start to construct the Cometary Database consisted of near-parabolic comets.
At these pages the new orbital solutions will be included systematically during the progress of our investigation.

For each comet are given three types of orbits:

The method of orbital calculations

Original and future orbits

Accuracy of the cometary orbit

Samples of near-parabolic comets

Near-parabolic comets in order of designation

Solar System Dynamics & Planetology Group, 2013. All rights reserved

We start to construct the Cometary Database consisted of near-parabolic comets. At these pages the new orbital solutions will be included systematically during the progress of our investigation.

For each comet are given three types of orbits:

The method of orbital calculations

Original and future orbits

Accuracy of the cometary orbit

Samples of near-parabolic comets

Near-parabolic comets in order of designation

Solar System Dynamics & Planetology Group, 2013. All rights reserved

We start to construct the Cometary Database consisted of near-parabolic comets.
At these pages the new orbital solutions will be included systematically during the progress of our investigation.