Orbital evolution of the Gefion and Adeona asteroid families: close encounters with massive asteroids and the Yarkovsky effect

Aims. We developed a six-part collisional evolution model of the main asteroid belt (MB) and used it to study the contribution of the different regions of the MB to the near-Earth asteroids (NEAs). Methods. We built a statistical code called ACDC that simulates the collisional evolution of the MB split into six regions (namely Inner, Middle, Pristine, Outer, Cybele and High-Inclination belts) according to the positions of the major resonances present there (ν6, 3:1J, 5:2J, 7:3J and 2:1J). We consider the Yarkovsky effect and the mentioned resonances as the main mechanism that removes asteroids from the different regions of the MB and delivers them to the NEA region. We calculated the evolution of the NEAs coming from the different source regions by considering the bodies delivered by the resonances and mean dynamical timescales in the NEA population. Results. Our model is in agreement with the major observational constraints associated with the MB, such as the size distributions of the different regions of the MB and the number of large asteroid families. It is also able to reproduce the observed NEAs with H < 16 and agrees with recent estimations for H < 20, but deviates for smaller sizes. We find that most sources make a significant contribution to the NEAs; however the Inner and Middle belts stand out as the most important source of NEAs followed by the Outer belt. The contributions of the Pristine and Cybele regions are minor. The High-Inclination belt is the source of only a fraction of the actual observed NEAs with high inclination, as there are dynamical processes in that region that enable asteroids to increase and decrease their inclinations.

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10. A Statistical Investigation of Asteroid Families: Preliminary Results

International Astronomical Union Colloquium ◽

10.1017/s0252921100070251 ◽

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.

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Orbital evolution of the terrestrial planets as a result of close encounters and collisions with planet-crossing asteroids

Planetary and Space Science ◽

10.1016/0032-0633(93)90117-k ◽

1993 ◽

Vol 41 (10) ◽

pp. 747-751 ◽

Cited By ~ 2

Author(s):

Adrian Brunini

Keyword(s):

Orbital Evolution ◽

Terrestrial Planets ◽

Close Encounters

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Low Velocity Encounters of Minor Bodies With the Outer Planets

International Astronomical Union Colloquium ◽

10.1017/s0252921100097256 ◽

1983 ◽

Vol 74 ◽

pp. 377-395

Author(s):

A. Carusi ◽

E. Perozzi ◽

G.B. Valsecchi

Keyword(s):

Solar System ◽

Orbital Evolution ◽

Outer Solar System ◽

Low Velocity ◽

Minor Body ◽

Outer Planets ◽

Close Encounters ◽

Satellite Capture

Previous studies of close encounters of minor bodies with Jupiter have shown that the perturbations are stronger either if the encounter is very deep or if the velocity of the minor body relative to the planet is low. In the present research we investigate the effects of low velocity encounters between fictitious minor bodies and the four outer planets. Two possible outcomes of this type of encounter are the temporary satellite capture of the minor body by the planet, and the exchange of perihelion with aphelion of the minor body orbit. Different occurrence rates of these processes are found for different planets, and the implications for the orbital evolution of minor bodies in the outer Solar System are discussed.

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Influence of the Yarkovsky force on Jupiter Trojan asteroids

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834715 ◽

2019 ◽

Vol 630 ◽

pp. A148 ◽

Cited By ~ 2

Author(s):

S. Hellmich ◽

S. Mottola ◽

G. Hahn ◽

E. Kührt ◽

D. de Niem

Keyword(s):

Thermal Properties ◽

Frequency Distribution ◽

Turning Point ◽

Opposite Effect ◽

Resonance Region ◽

Orbital Evolution ◽

Trojan Asteroids ◽

Size Frequency Distribution ◽

Yarkovsky Effect

Aims. We investigate the influence of the Yarkovsky force on the long-term orbital evolution of Jupiter Trojan asteroids. Methods. Clones of the observed population with different sizes and different thermal properties were numerically integrated for 1 Gyr with and without the Yarkovsky effect. The escape rate of these objects from the Trojan region as well as changes in the libration amplitude, eccentricity, and inclination were used as a metric of the strength of the Yarkovsky effect on the Trojan orbits. Results. Objects with radii R ≤ 1 km are significantly influenced by the Yarkovsky force. The effect causes a depletion of these objects over timescales of a few hundred million years. As a consequence, we expect the size-frequency distribution of small Trojans to show a shallower slope than that of the currently observable population (R ≳ 1 km), with a turning point between R = 100 m and R = 1 km. The effect of the Yarkovsky acceleration on the orbits of Trojans depends on the sense of rotation in a complex way. The libration amplitude of prograde rotators decreases with time while the eccentricity increases. Retrograde rotators experience the opposite effect, which results in retrograde rotators being ejected faster from the 1:1 resonance region. Furthermore, for objects affected by the Yarkovsky force, we find indications that the effect tends to smooth out the differences in the orbital distribution between the two clouds.

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Planetary Close Encounters: The Engine of Cometary Orbital Evolution

The Dynamics of Small Bodies in the Solar System ◽

10.1007/978-94-015-9221-5_18 ◽

1999 ◽

pp. 187-196 ◽

Cited By ~ 1

Author(s):

G. B. Valsecchi

Keyword(s):

Orbital Evolution ◽

Close Encounters

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The relationship between the `limiting' Yarkovsky drift speed and asteroid families' Yarkovsky V-shape

Serbian Astronomical Journal ◽

10.2298/saj2000025m ◽

2020 ◽

pp. 25-41

Author(s):

I. Milic-Zitnik

Keyword(s):

Interesting Property ◽

Parent Body ◽

Mean Motion Resonances ◽

Mean Motion ◽

Drift Speed ◽

Yarkovsky Effect ◽

The Mean ◽

The Relationship ◽

Asteroid Families

The Yarkovsky effect is an important force to consider in order to understand the long-term dynamics of asteroids. This non-gravitational force affects the orbital elements of objects revolving around a source of heat, especially their semi-major axes. Following the recently defined `limiting' value of the Yarkovsky drift speed at 7x10-5 au/Myr in Milic Zitnik (2019) (below this value of speed asteroids typically jump quickly across the mean motion resonances), we decided to investigate the relation between the asteroid family Yarkovsky V-shape and the `limiting' Yarkovsky drift speed of asteroid's semi-major axes. We have used the known scaling formula to calculate the Yarkovsky drift speed (Spoto et al. 2015) in order to determine the inner and outer `limiting' diameters (for the inner and outer V-shape borders) from the `limiting' Yarkovsky drift speed. The method was applied to 11 asteroid families of different taxonomic classes, origin type and age, located throughout the Main Belt. Here, we present the results of our calculation on relationship between asteroid families' V-shapes (crossed by strong and/or weak mean motion resonances) and the `limiting' diameters in the (a, 1=D) plane. Our main conclusion is that the `breakpoints' in changing V-shape of the very old asteroid families, crossed by relatively strong mean motion resonances on both sides very close to the parent body, are exactly the inverse of `limiting' diameters in the a versus 1=D plane. This result uncovers a novel interesting property of asteroid families' Yarkovsky V-shapes.

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Orbital evolution of Mars-crossing asteroids

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3566 ◽

2020 ◽

Vol 500 (3) ◽

pp. 3569-3578

Author(s):

I Wlodarczyk

Keyword(s):

Solar System ◽

Significant Influence ◽

Orbital Evolution ◽

The Sun ◽

Lyapunov Time ◽

Near Earth Objects ◽

Orbital Analysis ◽

Asteroid Families

ABSTRACT This study is an orbital analysis of the interesting Mars-crossing asteroids (MCAs), also known as Mars-crosser (MC) asteroids or Mars-crossers (MCs). We computed that after 100 million years (Myr), approximately 66 ${{\ \rm per\ cent}}$ of all known MCs are ejected out of the Solar System by collision with the Sun, the planets, Ceres, Pallas, Vesta, or Hygiea. The rate of MC migration is high. Thus, this population of MCs would be supplied by just as many asteroids from outside the Solar System. We estimated the rate at which near-Earth objects were created from MCs throughout a 100 Myr period, with Atiras accounting for nearly 3 ${{\ \rm per\ cent}}$ of these objects, over 2 ${{\ \rm per\ cent}}$ were Atens, nearly 7.5 ${{\ \rm per\ cent}}$ were Apollos, approximately 9${{\ \rm per\ cent}}$ were Amors, and nearly 0.4 ${{\ \rm per\ cent}}$ became Centaurs. These results were calculated with 10 000 yr output intervals. Furthermore, 0.028${{\ \rm per\ cent}}$ of all the starting MCs were in retrograde orbits for at least 10 000 yr. We found that majority of the remaining MCs have migrated into the region of three asteroid families: Phocaea, Hungaria, and Flora. We calculated a small but significant influence of Ceres, Pallas, Vesta, and Hygiea on the orbital evolution of the MCs. From the AstDys catalogue, we found that the largest number of studied numbered MCs have their Lyapunov time (LT) in the range 2–4 kyr. Using the orbfit software, we computed the LT of selected MCs in retrograde orbits, and obtained an LT of between 540 yr (asteroid 2016 DR1) and 71 000 yr (asteroid 42887 1999 RV155).

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