scholarly journals 10. A Statistical Investigation of Asteroid Families: Preliminary Results

1977 ◽  
Vol 39 ◽  
pp. 327-332
Author(s):  
A. Carusi ◽  
E. Massaro
Keyword(s):  
Orbital Evolution ◽  
Statistical Investigation ◽  
Correct Identification ◽  
Physical Origin ◽  
Preliminary Results ◽  
Clustering Technique ◽  
Proper Elements ◽  
Statistical Relevance ◽  
Asteroid Families

The correct identification of asteroid families is a prerequisite for understanding their nature, their orbital evolution and their physical origin. For this reason, a statistical investigation of asteroid families has been carried out, using a new clustering technique developed by A. I. Gavrishin. Proper elements for 2764 asteroids (1810 numbered and 954 Palomar-Leiden-Survey (PLS) asteroids) have been computed. Using these data, the Gavrishin method gives only ten significant classes. Five of them are coincident with the Hirayama families 1, 2, 3, 5, and the Flora group, that cannot be univocally subdivided. The PLS families are recognized. Furthermore many small-sized families reported by several authors lose their statistical relevance.

Asteroid families: evidence of ageing of the proper elements

Icarus ◽  
2004 ◽  
Vol 169 (2) ◽  
pp. 341-356 ◽  
Author(s):  
A. Dell'Oro ◽  
G. Bigongiari ◽  
P. Paolicchi ◽  
A. Cellino
Keyword(s):  
Proper Elements ◽  
Asteroid Families

scholarly journals Asteroid Proper Elements: The Big Picture

1994 ◽  
Vol 160 ◽  
pp. 143-158 ◽  
Author(s):  
Zoran Knežević ◽  
Andrea Milani
Keyword(s):  
Point Of View ◽  
Dynamical Structure ◽  
Main Belt ◽  
Secular Resonances ◽  
Mean Motion Resonances ◽  
Mean Motion ◽  
Proper Elements ◽  
Big Picture ◽  
Linear And Nonlinear ◽  
Asteroid Families

Four perturbation theories presently used to compute asteroid proper elements are reviewed, and their results are briefly discussed (Milani and Knežević, 1990, 1992, 1994, for low to moderate eccentricity/inclination main belt objects; Lemaitre and Morbidelli, 1994, for high e, I objects; Milani, 1993, for Trojans; Schubart, 1982, 1991 for Hildas). The most important recent improvements are described, in particular those pertaining to the upgrades of the previous analytic and semianalytic solutions. The dynamical structure of the asteroid main belt, as defined by the low order mean motion resonances and by linear and nonlinear secular resonances, is considered from the point of view of the effects of these resonances on the accuracy and/or reliability of the computation of proper elements and on the reliability of the identification of asteroid families.

Families among the Hildas and Trojans

2018 ◽  
Vol 14 (A30) ◽  
pp. 24-25
Author(s):  
Tamara A. Vinogradova
Keyword(s):  
Empirical Method ◽  
Proper Elements ◽  
Asteroid Families

AbstractA search for asteroid families among the Hildas and Jupiter Trojans was performed with the use of a new set of proper elements. The proper elements were calculated by the empirical method. Besides well known families, several new probable families were found in addition.

scholarly journals Numerical mean elements for asteroid orbits

1996 ◽  
Vol 172 ◽  
pp. 165-170 ◽  
Author(s):  
Anne Lemaitre
Keyword(s):  
Body Problem ◽  
Minor Planets ◽  
Proper Elements ◽  
N Body Problem ◽  
Double Averaging ◽  
The Mean ◽  
Osculating Elements ◽  
Mean Elements ◽  
Asteroid Families

In the context of the search of asteroid families (i.e. identification of minor planets as potential fragments of an old bigger body), the calculation of proper elements plays an important role. They are quasi-invariants of the motion, obtained by a double averaging process of the restricted N-body problem; firstly the osculating elements are averaged over the short periodic terms (namely the longitudes of the asteroid and of the perturbing planets) so to get the mean elements, and secondly, the mean elements are averaged over the long periodic terms (longitudes of the pericenters and of the nodes of the asteroid and of the perturbing planets) to obtain the proper elements.

scholarly journals Stellar Counter-Rotation Along the Hubble Sequence: A Probe for Galaxy Formation Scenarios

1999 ◽  
Vol 186 ◽  
pp. 161-164
Author(s):  
F. Prada ◽  
C.M. Gutiérrez
Keyword(s):  
Galaxy Formation ◽  
General Problem ◽  
Early Type ◽  
Physical Origin ◽  
Barred Galaxies ◽  
Preliminary Results ◽  
Hubble Sequence ◽  
Counter Rotation

We present some preliminary results of an on-going project to investigate the phenomenon of counter-rotation in galaxies. The analysis of two Sb and two barred galaxies shows the presence of stellar counter-rotating components in the central 1 to 3 kpc of each galaxy. This, along with similar structures found in ellipticals and early-type spirals, demonstrate that the counter-rotation extends along the Hubble sequence. The physical origin of these features is briefly discussed stressing the possible relevance of this phenomenon in understanding the general problem of galaxy formation.

scholarly journals Asteroid Family Identification: History and State of the Art

2015 ◽  
Vol 10 (S318) ◽  
pp. 16-27 ◽  
Author(s):  
Zoran Knežević
Keyword(s):  
State Of The Art ◽  
The State ◽  
Classification Methods ◽  
Data Set ◽  
The Third ◽  
Proper Elements ◽  
The Future ◽  
History Of ◽  
Asteroid Families ◽  
Collisional Evolution

AbstractThe history of asteroid families, from their discovery back in 1918, until the present time, is briefly reviewed. Two threads have been followed: on the development of the theories of asteroid motion and the computation of proper elements, and on the methods of classification themselves. Three distinct periods can be distinguished: the first one until mid-1930s, devoted to discovery and first attempts towards understanding of the properties of families; the second one, until early 1980s, characterized by a growing understanding of their importance as key evidence of the collisional evolution; the third one, characterized by an explosion of work and results, comprises the contemporary era. An assessment is given of the state-of-the-art and possible directions for the future effort, focusing on the dynamical studies, and on improvements of classification methods to cope with ever increasing data set.

scholarly journals Secular evolution of asteroid families: the role of Ceres

2015 ◽  
Vol 10 (S318) ◽  
pp. 46-54 ◽  
Author(s):  
Bojan Novaković ◽  
Georgios Tsirvoulis ◽  
Stefano Marò ◽  
Vladimir Đošović ◽  
Clara Maurel
Keyword(s):  
Numerical Simulations ◽  
Main Belt ◽  
Secular Resonance ◽  
Secular Evolution ◽  
Secular Dynamics ◽  
Proper Elements ◽  
Post Impact ◽  
Actual Shape ◽  
Asteroid Families

AbstractWe consider the role of the dwarf planet Ceres on the secular dynamics of the asteroid main belt. Specifically, we examine the post impact evolution of asteroid families due to the interaction of their members with the linear nodal secular resonance with Ceres. First, we find the location of this resonance and identify which asteroid families are crossed by its path. Next, we summarize our results for three asteroid families, namely (1726) Hoffmeister, (1128) Astrid and (1521) Seinajoki which have irregular distributions of their members in the proper elements space, indicative of the effect of the resonance. We confirm this by performing a set of numerical simulations, showcasing that the perturbing action of Ceres through its linear nodal secular resonance is essential to reproduce the actual shape of the families.

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