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

2020 ◽  
Author(s):  
Volodymyr Troianskyi ◽  
Keyword(s):  
Numerical Modelling ◽  
Thermal Parameters ◽  
Orbital Elements ◽  
Main Belt ◽  
Preliminary Results ◽  
Yarkovsky Effect ◽  
Photometric Observations

<p align="justify">The main objective of the study is the verification of the V-type rotation distribution. Though numerical modelling, Nesvorny et al. <span lang="en-US">(</span>2008<span lang="en-US">)</span> showed that asteroids can migrate <span lang="en-US">through</span> 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 < i deg < 10 deg) typically have retrograde rotation and thermal parameters that maximize <span lang="en-US">the</span> 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 < i < 6 deg) should be predominantly rotating prograde (60% of objects).</p> <p align="justify">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 <span lang="en-US">un-matching</span> 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.</p>

Shape models and dynamical properties of basaltic asteroids outside the dynamical Vesta family

2021 ◽  
Author(s):  
Volodymyr Troianskyi ◽  
Dagmara Oszkiewicz ◽  
Anna Marciniak ◽  
Pawel Kankiewicz ◽  
Dora Fohring ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Parent Body ◽  
Thermal Parameters ◽  
Orbital Elements ◽  
Main Belt ◽  
Preliminary Results ◽  
Shape Models ◽  
Photometric Observations ◽  
Current Location ◽  
Dynamical Properties

<p>Through numerical modeling, Nesvorny et al. (2008) showed that asteroids can migrate due to Yarkovsky drift and resonances to outside of 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 < i deg < 10 deg) typically have retrograde rotations and thermal parameters that maximize Yarkovsky drift rates. These autors also 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 < i < 6 deg) should be predominantly prograde rotators.</p> <p>We performe photometric observations and determine spins and shapes of V-type objects in Cell I and Cell II in order to characterize the dynamical properties of these asteroids more accurately. The results of dynamical modelling show that some asteroids may have migrated to their current location from the Vesta family within ~2 Gy. There are objects, however, whose origin in another parent body may also be plausible. This may support the hypothesis that the number of differentiated basaltic objects in the inner and middle Main Belt should be much higher than previously assumed. We will present preliminary results for the first ~10 asteroids in Cell I and Cell II.</p>

scholarly journals Observational Data and Orbits of the Asteroids Discovered at the Molėtai Observatory in 2008–2009

2016 ◽  
Vol 25 (4) ◽  
Author(s):  
K. Černis ◽  
I. Wlodarczyk ◽  
J. Zdanavičius
Keyword(s):  
Observational Data ◽  
Minor Planet ◽  
Orbital Elements ◽  
Main Belt ◽  
Ccd Observations ◽  
Near Earth Objects ◽  
Asteroids And Comets

AbstractWe present the statistics of the asteroids observed and discovered at the Molėtai Observatory, Lithuania, in 2008–2009 within the project for astrometric observations of the near-Earth objects (NEOs), the main belt asteroids and comets. CCD observations of the asteroids were obtained with the 35/51-cm Maksutov-type meniscus telescope. In the Minor Planet Circulars and the Minor Planet Electronic Circulars (2008–2009), 11 900 astrometric positions of 2522 asteroids were published. Among them 95 were new asteroids, including four belonging to the Trojan group: (352655) 2008QX28, 2008 SE8, (353194) 2009 SM100 and (264068) 2009 SQ148. For the asteroids discovered at Molėtai their precise orbits are calculated. Because of short observational arc, a few asteroids have low-precision orbits and some asteroids are considered lost. For the three Main Belt asteroids with low-precision orbital elements, 2008 QP32, 2008 SD8 and 2008 SG150, we present their ephemerides for 2017. They can be brighter than 20 mag.

scholarly journals Photometric Observations of Three Double Stars by the Occultation Method — Comparison with Interferometric Results and with Preliminary Results of HIPPARCOS

1992 ◽  
Vol 135 ◽  
pp. 546-548
Author(s):  
M. Froeschlé ◽  
C. Meyer
Keyword(s):  
Diffraction Pattern ◽  
Method Comparison ◽  
Short Description ◽  
Double Star ◽  
Preliminary Results ◽  
Double Stars ◽  
Photometric Observations

AbstractWe first briefly recall the geometry of the occultation of a double star by the Moon’s edge. Then we give a short description of the principle of the formation of the diffraction pattern. We present the results for three double stars and compare them with those obtained by other methods.

Observational Data and Orbits of the Asteroids Discovered at the Baldone Observatory in 2008–2013

2015 ◽  
Vol 24 (3) ◽  
Author(s):  
K. Černis ◽  
I. Wlodarczyk ◽  
I. Eglitis
Keyword(s):  
Observational Data ◽  
Ccd Camera ◽  
Minor Planet ◽  
Orbital Elements ◽  
Main Belt ◽  
Schmidt Telescope ◽  
Ccd Observations ◽  
Near Earth Objects ◽  
Asteroids And Comets

AbstractThe paper presents statistics of the asteroids observed and discovered at the Baldone Observatory, Latvia, in 2008–2013 within the project for astrometric observations of the near-Earth objects (NEOs), the main belt asteroids and comets. CCD observations of the asteroids were obtained with the 0.80/1.20 m, f/3 Schmidt telescope and a ST-10XME 15 × 10 mm CCD camera. In the Minor Planet Circulars and the Minor Planet Electronic Circulars (2008–2013) we published 3511 astrometric positions of 826 asteroids. Among them, 43 asteroids were newly discovered at Baldone. For 36 of these asteroids the precise orbits are calculated. Because of short observational arc and small number of observations, a few asteroids have low-precision orbits and their tracks have been lost. For seven objects with poorly known orbits we present their ephemerides for 2015–2016. The orbits and the evolution of orbital elements of two asteroids, (428694) 2008 OS9 from the Apollo group and the Centaur (330836) Orius (2009 HW77), are recalculated including new observations obtained after 2011.

Observation of 44(Nysa) Asteroid by IST60 Telescope

2018 ◽  
Vol 14 (A30) ◽  
pp. 40-40
Author(s):  
Remziye Canbay ◽  
Fulin Gursoy
Keyword(s):  
Minor Planet ◽  
Web Interface ◽  
Orbital Elements ◽  
Main Belt

AbstractIn this study, the main belt asteroid (44) Nysa, which is also a known member of the Nysian asteroid family, was observed by IST60 telescope. The orbital elements were compared with MPO(Minor Planet Center) and NASA Horizons Web-Interface results.

Detection of the Yarkovsky effect for main-belt asteroids

Icarus ◽  
2004 ◽  
Vol 170 (2) ◽  
pp. 324-342 ◽  
Author(s):  
David Nesvorný ◽  
William F. Bottke
Keyword(s):  
Main Belt ◽  
Yarkovsky Effect

scholarly journals New multi-part collisional model of the main belt: the contribution to near-Earth asteroids

2020 ◽  
Vol 639 ◽  
pp. A9
Author(s):  
P. S. Zain ◽  
G. C. de Elía ◽  
R. P. Di Sisto
Keyword(s):  
Significant Contribution ◽  
Asteroid Belt ◽  
Size Distributions ◽  
Main Belt ◽  
Yarkovsky Effect ◽  
Source Regions ◽  
Main Asteroid Belt ◽  
Near Earth Asteroids ◽  
Asteroid Families ◽  
Collisional Evolution

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.

Automatic prediction, selection and analysis of occultations to characterize asteroid family members

2021 ◽  
Author(s):  
Rodrigo Leiva ◽  
Paolo Tanga ◽  
Luana Liberato
Keyword(s):  
Drift Rate ◽  
Family Members ◽  
Age Determination ◽  
Angular Size ◽  
Processing System ◽  
Orbital Elements ◽  
Yarkovsky Effect ◽  
Stellar Occultation ◽  
The Status

&lt;p&gt;A new 50 cm telescope, the UniversCity telescope, was recently installed at Plateau de Calern, France, to survey stellar occultation by asteroids from collisional families. A stellar occultation occurs when an asteroid passes in front of a distant star blocking its light temporarily. Measuring the time of the occultations provides an accurate astrometric measurement of the asteroid, comparable with the angular size of the asteroid. Thanks to the astrometric catalog from the Gaia mission, astrometry accuracy from occultation reaches a few milliarcseconds.&lt;/p&gt;&lt;p&gt;The astrometry from the survey is used in turn to improve the orbit of the asteroid, while the duration of the occultation is used to constrain physical characteristics and search for binarity. The orbit improvement aims to detect and measure the drift rate in the orbital elements of asteroids due to the Yarkovsky effect, a non-gravitational force responsible for scattering the orbital elements of collisional family members. Combining the magnitude of the Yarkovsky drift rate from the occultation survey with the accumulated drift since the originating collision, the age determination of the collisional family can be obtained.&lt;/p&gt;&lt;p&gt;The occultation survey takes advantage of the stellar occultation technique and the Gaia astrometric catalog to systematically derive accurate astrometric measurements for collisional family members.&lt;/p&gt;&lt;p&gt;The telescope will be operated robotically, dedicating most of its time to the occultation survey, with a small percentage of time to other science cases. The large number of family members and candidates to stellar occultations demands the automation of the occultation prediction, the selection and prioritization of occultation events, telescope scheduling, data reduction, and data analysis.&lt;/p&gt;&lt;p&gt;The occultation predictions are updated regularly in the light of new astrometric measurements from traditional astrometry and from occultations measurements. The occultations predicted to be visible from the UniversCity site are prioritized based on their chances of detection and contribution to the family age determination. The data acquired each night is automatically reduced to obtain light curves from which detection candidates are analyzed.&lt;/p&gt;&lt;p&gt;We will present the status of the project and the development and performances of the automatic prediction and processing system.&lt;/p&gt;

scholarly journals Simultaneous Multiwavelength Observations of Dwarf Novae Systems at Quiescence and in Outburst

1996 ◽  
Vol 158 ◽  
pp. 79-80
Author(s):  
G. Tovmassian ◽  
J. Echevarria ◽  
E. Perez ◽  
D. H. P. Jones ◽  
M. Shara ◽  
...  
Keyword(s):  
Dwarf Novae ◽  
Preliminary Results ◽  
International Program ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Photometric Observations ◽  
Northern And Southern Hemispheres ◽  
Multiwavelength Observations

The results of photometric and spectroscopic observations of dwarf novae are presented. The data were obtained during an international program of multiwavelength observations, held in 1986 February at several observatories, of dwarf novae during the first and subsequent days of outburst. During the campaign numerous dwarf novae were monitored in order to catch them in outburst. Preliminary results and analysis of some objects are reported elsewhere. A total of 30 dwarf novae were observed in the northern and southern hemispheres. Among them 37% were caught in outburst, including 10% on the rise to outburst and 17% in decline. Photometric observations were carried out in the UBVRI system and colour indexes were calculated.

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