Detection of the Yarkovsky effect for main-belt asteroids

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.

Download Full-text

Verification of the V-type asteroids rotation distribution outside Vesta family

10.5194/epsc2020-1128 ◽

2020 ◽

Author(s):

Volodymyr Troianskyi ◽

Keyword(s):

Numerical Modelling ◽

Thermal Parameters ◽

Orbital Elements ◽

Main Belt ◽

Preliminary Results ◽

Yarkovsky Effect ◽

Photometric Observations

The main objective of the study is the verification of the V-type rotation distribution. Though numerical modelling, Nesvorny et al. (2008) showed that asteroids can migrate through Yarkovsky effect and resonaces outside the boundaries of the Vesta family. In particular they found that objects which end up in the scattered resonances region (so-called Cell I, defined by orbital elements 2.2 AU < a < 2.3 AU, 0.05 < e < 0.2, 0 the Yarkovsky drift. Consequently, most of the V-types in Cell I should be retrograde rotating. Similarly showed that asteroids migrating to the low inclination region (Cell II defined by 2.32 AU < a < 2.48 AU, 0.05 < e < 0.2, 2 deg We perform photometric observations and determine spins and shapes of V-type objects in Cell I and II to verify the predicted statistics of sense of rotation. Finding significantly un-matching statistics for rotational properties may strengthen the idea that there may be fragments of other (than Vesta) differentiated planetesimals in the inner main belt. We show preliminary results for the first few asteroids in Cell I and II.

Download Full-text

Detecting the Yarkovsky effect using the GAIA DR2 catalogue

10.5194/epsc2020-953 ◽

2020 ◽

Author(s):

Karolina Dziadura ◽

Dagmara Oszkiewicz ◽

Przemysław Bartczak

Keyword(s):

Direct Detection ◽

Close Approach ◽

Fortran Program ◽

Main Belt ◽

Small Bodies ◽

Yarkovsky Effect ◽

Impact Monitoring ◽

The Times ◽

First Time ◽

Gaia Dr2

The orbital motion of small bodies is affected by the Yarkovsky effect. First-time the effect was proposed by Yarkovsky in 1901 and then popularized by &#214;pik in 1950s. However, the first direct detection was only made in 2003 using radar observations. Nowadays there are hundreds of detections for NEAs and only a few for Main-Belt objects. In this work, I attempt to detect the Yarkovsky effect among multiple Main-Belt objects and other asteroids. I will show preliminary results for five asteroids using the OrbFit software. &#160;OrbFit is a Fortran program for orbit propagation, ephemerides computation, orbit determination, close approach analysis, and impact monitoring. Orbits were calculated using FitObs with and without the Yarkovsky effect. Next, the ephemeris were computed for the times of GAIA observations and compared with the GAIA DR2 data.

Download Full-text

Transit of asteroids across the 7/3 Kirkwood gap under the Yarkovsky effect

Astronomy and Astrophysics ◽

10.1051/0004-6361/201937261 ◽

2020 ◽

Vol 637 ◽

pp. A19

Author(s):

Yang-Bo Xu ◽

Li-Yong Zhou ◽

Wing-Huen Ip

Keyword(s):

Solar System ◽

Numerical Simulations ◽

Observational Data ◽

Family Members ◽

Main Belt ◽

Mean Motion Resonances ◽

Yarkovsky Effect ◽

Principal Source ◽

Kirkwood Gap ◽

Near Earth Objects

The Yarkovsky effect plays an important role in asteroids drifting in the inner Solar System. In the main belt, many asteroids are continuously pushed by the Yarkovsky effect into regions of different mean motion resonances (MMRs) and then ejected after a period of time, due to the instability of MMRs. They are considered as the principal source of near-Earth objects. In this paper, we investigate the effects of the 7/3 MMR with Jupiter (J7/3 MMR) on the transportation of asteroids from the Koronis family and the Eos family that reside, respectively, on the inner and outer sides of the resonance using numerical simulations. The J7/3 MMR acts like a selective barrier to migrating asteroids. The fraction of asteroids that successfully cross through the resonance and the escape rate from the resonance are found to depend on the Yarkovsky drifting rate, the initial inclination and the migrating direction. The excitation of eccentricity and inclination due to the combined influence from both the resonance and the Yarkovsky effect are discussed. Only the eccentricity can be pumped up considerably, and it is attributed mainly to the resonance. In the observational data, family members are also found in the resonance and on the opposite side of the resonance with respect to the corresponding family centre. The existence of these family members is explained using our results of numerical simulations. Finally, the replenishment of asteroids in the J7/3 MMR and its transportation of asteroids are discussed.

Download Full-text

Brief summary of Kleť photographic search programme for minor planets

International Astronomical Union Colloquium ◽

10.1017/s0252921100031419 ◽

1999 ◽

Vol 173 ◽

pp. 189-192

Author(s):

J. Tichá ◽

M. Tichý ◽

Z. Moravec

Keyword(s):

Ccd Camera ◽

Minor Planet ◽

Minor Planets ◽

Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Download Full-text

Assessing Accessibility of Main-Belt Asteroids Using Support Vector Machines for Regression

2020 Chinese Automation Congress (CAC) ◽

10.1109/cac51589.2020.9327355 ◽

2020 ◽

Author(s):

Haohan Yang ◽

Kuoxiang Zhang ◽

Haibin Shang

Keyword(s):

Support Vector Machines ◽

Support Vector ◽

Main Belt ◽

Vector Machines

Download Full-text

A simulated gravity field estimation for the main belt comet 133P/Elst-Pizarro

Astrophysics and Space Science ◽

10.1007/s10509-021-03964-0 ◽

2021 ◽

Vol 366 (6) ◽

Author(s):

Wutong Gao ◽

Jianguo Yan ◽

Weitong Jin ◽

Chen Yang ◽

Linzhi Meng ◽

...

Keyword(s):

Gravity Field ◽

Main Belt ◽

Field Estimation

Download Full-text

New Tools for the Optimized Follow-Up of Imminent Impactors

Universe ◽

10.3390/universe7010010 ◽

2021 ◽

Vol 7 (1) ◽

pp. 10

Author(s):

Maddalena Mochi ◽

Giacomo Tommei

Keyword(s):

Orbit Determination ◽

Main Belt ◽

Impact Monitoring ◽

The Earth ◽

Current Observation ◽

Short Period ◽

Fly Eye ◽

Near Earth Asteroids ◽

Near Earth Objects

The solar system is populated with, other than planets, a wide variety of minor bodies, the majority of which are represented by asteroids. Most of their orbits are comprised of those between Mars and Jupiter, thus forming a population named Main Belt. However, some asteroids can run on trajectories that come close to, or even intersect, the orbit of the Earth. These objects are known as Near Earth Asteroids (NEAs) or Near Earth Objects (NEOs) and may entail a risk of collision with our planet. Predicting the occurrence of such collisions as early as possible is the task of Impact Monitoring (IM). Dedicated algorithms are in charge of orbit determination and risk assessment for any detected NEO, but their efficiency is limited in cases in which the object has been observed for a short period of time, as is the case with newly discovered asteroids and, more worryingly, imminent impactors: objects due to hit the Earth, detected only a few days or hours in advance of impacts. This timespan might be too short to take any effective safety countermeasure. For this reason, a necessary improvement of current observation capabilities is underway through the construction of dedicated telescopes, e.g., the NEO Survey Telescope (NEOSTEL), also known as “Fly-Eye”. Thanks to these developments, the number of discovered NEOs and, consequently, imminent impactors detected per year, is expected to increase, thus requiring an improvement of the methods and algorithms used to handle such cases. In this paper we present two new tools, based on the Admissible Region (AR) concept, dedicated to the observers, aiming to facilitate the planning of follow-up observations of NEOs by rapidly assessing the possibility of them being imminent impactors and the remaining visibility time from any given station.

Download Full-text