Warsaw Catalogue of cometary orbits: 119 near-parabolic comets (original) (raw)
Related papers
Monthly Notices of the Royal Astronomical Society, 2013
Dynamics of a complete sample of small perihelion distance near-parabolic comets discovered in the years 2006-2010 are studied (i.e. of 22 comets of q osc < 3.1 au). First, osculating orbits are obtained after a very careful positional data inspection and processing, including where appropriate, the method of data partitioning for determination of pre-and post-perihelion orbit for tracking then its dynamical evolution. The non-gravitational acceleration in the motion is detected for 50 per cent of investigated comets, in a few cases for the first time. Different sets of non-gravitational parameters are determined from preand post-perihelion data for some of them. The influence of the positional data structure on the possibility of the detection of non-gravitational effects and the overall precision of orbit determination is widely discussed. Secondly, both original and future orbits were derived by means of numerical integration of swarms of virtual comets obtained using a Monte Carlo cloning method. This method allows us to follow the uncertainties of orbital elements at each step of dynamical evolution. The complete statistics of original and future orbits that includes significantly different uncertainties of 1/avalues is presented, also in the light of our results obtained earlier. Basing on 108 comets examined by us so far, we conclude that only one of them, C/2007 W1 Boattini, seems to be a serious candidate for an interstellar comet. We also found that 53 per cent of 108 nearparabolic comets escaping in the future from the Solar system, and the number of comets leaving the Solar system as so called Oort spike comets (i.e. comets suffering very small planetary perturbations) is 14 per cent. A new method for cometary orbit quality assessment is also proposed by means of modifying the original method, introduced by Marsden, Sekanina & Everhart. This new method leads to a better diversification of orbit quality classes for contemporary comets.
The catalogue of cometary orbits and their dynamical evolution
Astronomy & Astrophysics
We present the CODE catalogue, the new cometary catalogue containing data for almost 300 long-period comets that were discovered before 2018. This is the first catalogue containing cometary orbits in the five stages of their dynamical evolution and covering three successive passages through the perihelion, with the exception of the hyperbolic comets which are treated in a different manner. Non-gravitational orbits are given for about 100 of these long-period comets, and their orbits obtained while neglecting the existence of non-gravitational acceleration are included for comparison. For many of the presented comets, different orbital solutions, based on the alternative force models or various subsets of positional data, are also provided. The preferred orbit is always clearly indicated for each comet.
A study of the original orbits of "hyperbolic" comets
Astronomy & Astrophysics, 2001
The problem of hyperbolic incoming orbits for single-apparition comets is investigated. In this context the effect of non-gravitational acceleration on cometary dynamics was analyzed for the sample of 33 "hyperbolic" comets. The orbital elements of each cometary orbit were determined by the least squares procedure based on positional observations. These osculating orbital elements serve as a basis for the determination of the incoming orbits. The new method of estimating the uncertainties of (1/a)ori based on a statistical approach to the orbit determinations is applied. For sixteen comets it was possible to determine the non-gravitational effects and original "non-gravitational" orbits. We show that for almost all the comets with detectable non-gravitational effects the incoming barycentric orbits changed from hyperbolic to elliptical when the non-gravitational effects were included. However, it was also ascertained that excess velocity at great distance are not cancelled by the nongravitational acceleration itself. We show that the non-gravitational effects are responsible for small modifications of the osculating elements (mainly eccentricity), which are sufficient, however, to obtain the elliptic original orbits for comets recognized in the literature as hyperbolic.
Non-gravitational effects change the original 1/a-distribution of near-parabolic comets
Astronomy & Astrophysics
Context. The original 1∕a-distribution is the only observational basis for the origin of long-period comets (LPCs) and the dynamical properties of the Oort Cloud. Although they are very subtle in the motion of these comets, non-gravitational effects can cause major changes in the original semimajor axis, 1∕aori. Aims. We obtained reliable non-gravitational orbits for as many LPCs with small perihelion distances of q < 3.1 au as possible, and determined the corresponding shape of the Oort spike. Methods. We determined the osculating orbits of each comet using several data-processing methods, and selected the preferred orbit using a few specific criteria. The distribution of 1∕aori for the whole comet sample was constructed using the individual Gaussian distribution we obtained for the preferred solution of each comet. Results. The derived distribution of 1∕aori for almost all known small-perihelion Oort spike comets was based on 64% of the non-gravitational orbits. This was compar...
New orbit recalculations of comet C/1890 F1 Brooks and its dynamical evolution
Monthly Notices of the Royal Astronomical Society
C/1890 F1 Brooks belongs to a group of nineteen comets used by Jan Oort to support his famous hypothesis on the existence of a spherical cloud containing hundreds of billions of comets with orbits of semimajor axes between 50 and 150 thousand au. Comet Brooks stands out from this group because of a long series of astrometric observations as well as nearly two-year long observational arc. Rich observational material makes this comet an ideal target for testing the rationality of an effort to recalculate astrometric positions on the basis of original (comet-star)-measurements using modern star catalogues. This paper presents the results of such new analysis based on two different methods: (i) automatic re-reduction based on cometary positions and the (comet-star)-measurements, and (ii) partially automatic re-reduction based on the contemporary data for originally used reference stars. We show that both methods offer a significant reduction of orbital elements uncertainties. Based on the most preferred orbital solution, the dynamical evolution of comet Brooks during three consecutive perihelion passages is discussed. We conclude that C/1890 F1 is a dynamically old comet that passed the Sun at a distance below 5 au during its previous perihelion passage. Furthermore, its next perihelion passage will be a little closer than during the 1890-1892 apparition. C/1890 F1 is interesting also because it suffered extremely small planetary perturbations when it travelled through the planetary zone. Therefore, in the next passage through perihelion it will be once again a comet from the Oort spike.
Long-term evolution of Oort Cloud comets: methods and comparisons
Monthly Notices of the Royal Astronomical Society, 2001
Two long-term simulation methods for cometary orbits, a Monte Carlo method and a direct integration method, are compared with each other. The comparison is done in seven inclination and perihelion distance intervals, and shows differences in dynamical lifetime and capture probabilities for the following main reasons. We use a finite energy step approximation in the Monte Carlo method and the method considers only close approaches with the planets. The differences can be taken into account statistically and it is possible to calculate the correction factors for the capture probability and dynamical lifetime in the Monte Carlo method. Both corrections depend on the inclination and on the value of the minimum energy step. The capture probabilities of the short-period comets originating in the Oort Cloud are calculated by the corrected Monte Carlo method and compared with published results.
New catalogue of one-apparition comets discovered in the years 1901–1950
Astronomy & Astrophysics, 2014
Context. The orbits of one-apparition comets discovered in the early part of the last century have formerly been determined with very different numerical methods and assumptions on the model of the solar system, including the number of planets taken into account. Moreover, observations of the comet-minus-star-type sometimes led to determination of the comet position that are less precise than what we can derive today by using a more modern star catalogue. Aims. We aim to provide a new catalogue of cometary orbits that are derived using a completely homogeneous data treatment, accurate numerical integration, and a modern model of the solar system. Methods. We collected the complete sets of observations for investigated comets from the original publications. Then we recalculated the cometary positions for the comet-minus-star-type of observations using the Positions and Proper Motions Star Catalogue, and applied a uniform method for the data selection and weighting. As a final result, new osculating orbits were determined. Secondly, dynamical calculations were performed to the distance of 250 AU from the Sun to derive original and future barycentric orbits for evolution backward and forward in time. These numerical calculations for a given object start from a swarm of virtual comets constructed using our osculating (nominal) orbit. In this way, we obtained the orbital element uncertainties of original and future barycentric orbits. Results. We present homogeneous sets of orbital elements for osculating, original, and future orbits for 38 one-apparition comets. Non-gravitational orbits are derived for thirteen of them.
Dynamics and orbital evolution of Oort cloud comets
Symposium - International Astronomical Union
Investigators generally conjecture a steady flux of new comets from the Oort cloud through the inner Solar system. Due to gravitational perturbations by major planets these objects may escape, become long period comets (LPCs) if their orbital periods P are larger than 200yr or become short period comets (SPCs) when their period is less than 200yr. SPCs are further divided in two types: the Halley type comets (HT, for P…
Where do long-period comets come from? 26 comets from the non-gravitational Oort spike
Monthly Notices of the Royal Astronomical Society, 2010
Since 1950, when Oort published his hypothesis, several important new facts have been established in this field. At present, there are still questions surrounding the apparent source region (or regions) of long-period comets, the definition of dynamically new comets and the characteristics of the hypothetical Oort Cloud. Our aim in this investigation is to look for the apparent source of selected long-period comets and to refine the definition of dynamically new comets. Based on pure gravitational original orbits, all comets studied in this paper are widely called dynamically new. However, we show that the incorporation of non-gravitational forces into the orbit determination process significantly changes the situation. We have determined the precise non-gravitational orbits of all investigated comets. Then, we have followed numerically their past and future motions during one orbital period. Applying the ingenious method of Sitarski of creating swarms of virtual comets compatible with observations, we have been able to derive the uncertainties of original and future orbital elements, as well as the uncertainties of previous and next perihelion distances. We conclude that the past and future evolutions of cometary orbits under Galactic tide perturbations is the only way to find which comets are really dynamically new. In our sample, fewer than 30 per cent of comets are, in fact, dynamically new. Most of these have small previous perihelion distances. However, 60 per cent of these will be lost on hyperbolic orbits in the future. This evidence suggests that the investigation into the apparent source of longperiod comets is challenging. We have also shown that a significant percentage of long-period comets can visit the zone of visibility during at least two or three consecutive perihelion passages.
Monthly Notices of the Royal Astronomical Society, 2015
In the first part of this research we extensively investigated and carefully determined osculating, original (when entering Solar system) and future (when leaving it), orbits of 22 near-parabolic comets with small perihelion distance (q osc < 3.1 au), discovered in years 2006-2010. Here, we continue this research with a detailed study of their past and future motion during previous and next orbital periods under the perturbing action of our Galactic environment. At all stages of our dynamical study, we precisely propagate in time the observational uncertainties of cometary orbits. For the first time in our calculations, we fully take into account individual perturbations from all known stars or stellar systems that closely (less than 3.5 pc) approach the Sun during the cometary motion in the investigated time interval of several million years. This is done by means of a direct numerical integration of the N-body system comprising of a comet, the Sun and 90 potential stellar perturbers. We show a full review of various examples of individual stellar action on cometary motion. We conclude that perturbations from all known stars or stellar systems do not change the overall picture of the past orbit evolution of longperiod comets. Their future motion might be seriously perturbed during the predicted close approach of Gliese 710 star but we do not observe significant energy changes. The importance of stellar perturbations is tested on the whole sample of 108 comets investigated by us so far and our previous results, obtained with only Galactic perturbations included, are fully confirmed. We present how our results can be used to discriminate between dynamically new and old near-parabolic comets and discuss the relevance of the so-called Jupiter-Saturn barrier phenomenon. Finally, we show how the Oort spike in the 1/a-distribution of near-parabolic comets is built from both dynamically new and old comets. We also point out that C/2007 W1 seems to be the first serious candidate for interstellar provenance.