DOCSLIB.ORG

An Analysis of the Region of the Phocaea Dynamical Family

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An Analysis of the Region of the Phocaea Dynamical Family Mon. Not. R. Astron. Soc. 398, 1512–1526 (2009) doi:10.1111/j.1365-2966.2009.15220.x An analysis of the region of the Phocaea dynamical family V. Carruba1,2 1IPD, UNIVAP, Sao˜ Jose´ dos Campos, SP, 12244-000, Brazil 2 Department of Mathematics, UNESP, Guaratingueta,´ SP, Brazil Downloaded from Accepted 2009 June 9. Received 2009 June 9; in original form 2009 March 10 ABSTRACT http://mnras.oxfordjournals.org/ In this work, I conduct a preliminary analysis of the Phocaea family region. I obtain families and clumps in the space of proper elements and proper frequencies, study the taxonomy of the asteroids for which this information is available, analyse the albedo and absolute magnitude distribution of objects in the area, obtain a preliminary estimate of the possible family age, study the cumulative size distribution and collision probabilities of asteroids in the region, the rotation rate distribution and obtain dynamical map of averaged elements and Lyapunov times for grids of objects in the area. Among my results, I identified the first clump visible only in the frequency domain, the at Fundação Coordenação de Aperfeiçoamento Pessoal Nível Superior on July 15, 2013 (6246) Komurotoru clump, obtained a higher limit for the possible age of the Phocaea family of 2.2 Byr, identified a class of Phocaea members on Mars-crossing orbits characterized by high Lyapunov times and showed that an apparently stable region on time-scales of 20 Myr near the ν6 secular resonance is chaotic, possibly because of the overlapping of secular resonances in the region. The Phocaea dynamical group seems to be a real S-type collisional family, formed up to 2.2 Byr ago, whose members with a large semimajor axis have been dynamically eroded by the interaction with the local web of mean-motion and secular resonances. Studying the long-term stability of orbits in the chaotic regions and the stability of family and clumps identified in this work remain challenges for future works. Key words: celestial mechanics – minor planets, asteroids. families and clumps in the region were recently identified by Foglia 1 INTRODUCTION & Masi (2004) and Gil-Hutton (2006). Among highly inclined asteroids [asteroids with sin(i) > 0.3, for One of the open questions about the Phocaea family is if the which the analytical theory used to obtain proper elements is not dynamical family is real or an artefact created by the stable island very accurate (Milani & Knezeviˇ c´ (1994)], the asteroids in the region between secular and mean-motion resonances, and the zone region of the Phocaea family are characterized by a very interest- of close encounters with Mars (Knezeviˇ c´ & Milani 2003). For the ing dynamics. The region of the Phocaea family is delimited by purpose of answering this and other questions in this work, I first the 7J:-2A mean-motion resonance at low a, by the 3J:-1A reso- re-obtained dynamical families in the space of proper element and nance at high a andbytheν6 = g − g6 (where g is the secular frequencies (Carruba & Michtchenko 2007, 2009), I studied the frequency of precession of the pericentre, and the suffix 6 refers spectroscopical and Sloan Digital Sky Survey Moving Objects Cat- to Saturn) secular resonance at low i (Knezeviˇ c´ & Milani 2003). alogue, fourth release (SDSS-MOC4) data for the region, reviewed A region of shallow close encounters with Mars appears at e> the current knowledge on geometric albedos and absolute mag- 0.3, but deep close encounters with Mars are made impossible by nitudes, obtained the Yarkovsky isolines, studied the cumulative the Kozai-class protection mechanism (Milani et al. 1989). The distribution and collision probabilities of family members and the Phocaea family itself is characterized by its interaction with the information on asteroid rotation rates, and the role that mean-motion ν6 − ν16 secular resonance [(g − g6) − (s − s6), where s is the and secular resonances have had in shaping the family. secular precession frequency of the asteroid node], and harmonics I found that, with the exception of the family around (19536) of this resonance are also present in the region. To better under- (1999 JM4), formerly associated with the clump around (2860) stand the interaction of the Phocaea family with the (ν6 − ν16) Pasacentennium, the families and clumps found by Gil-Hutton secular resonance, the family was recently obtained in the (n, g, (2006) are now substructures of the Phocaea family. I identified new g − s) frequency domain by Carruba & Michtchenko (2009). Other clumps in a proper element and frequency space, and in particular I found the first ‘frequency-only’ clump around (6246) Komurotoru. A preliminary analysis of Yarkovsky isolines shows that the fam- E-mail: [email protected] ily can be up to 2.2 Byr old. Dynamical maps of the region showed C 2009 The Author. Journal compilation C 2009 RAS An analysis of the region of the Phocaea dynamical family 1513 140 80 N N 0 0 N N min A min B max(N ) max(N ) i 70 i 120 60 100 50 80 min min 40 N N 60 30 Downloaded from 40 20 20 10 0 0 50 100 150 200 250 300 350 400 0.2 0.4 0.6 0.8 1 v [m/s] f ["/yr] cutoff cutoff http://mnras.oxfordjournals.org/ Figure 1. The average number N 0, N min and the maximum number max (Ni) of asteroids as a function of the velocity cut-off (panel A), and of the frequency cut-off (panel B), for the asteroids in the region of the Phocaea family. us that there exist regions that are dynamically stable on the time- is8.AscanbeseeninFig.1,thefactthatmax(Ni) is not much scales of the integration, but yet deprived of asteroids. Such regions, larger than Nmin may be a hint that the families dominate the local all characterized by very low values of Lyapunov times, are either background of objects (see Section 6). associated with Mars-crossing orbits, or are near the border of the For what concerns the domain of proper frequencies, since the ν6 secular resonance separatrix. Understanding the long-term sta- Phocaea group is characterized by its interaction with the (g − s − bility of orbits in the chaotic regions and the stability of family and g6 + s6) resonance, or (ν6 − ν16)(Knezeviˇ c´ & Milani 2003, see clumps identified in this work will be the subject of a next paper on also Section 8), following the approach of Carruba & Michtchenko at Fundação Coordenação de Aperfeiçoamento Pessoal Nível Superior on July 15, 2013 this subject. (2009), I determined the family with a metric of the form n 2 2 DYNAMICAL FAMILIES AND CLUMPS f = h + h (g)2 + h ((g − s))2, (2) 1 h 2 3 IN THE REGION 0 = = = I start my analysis of the Phocaea family region by re-deriving clas- (where h1 h2 h3 1) rather than with the ‘standard fre- + sical and frequency families and clumps in the area. I identify the quency metric’ in the (n, g, g s) domain of Carruba & members of the dynamical families in the region using the classical Michtchenko (2007). I determined the nominal frequency cut-off hierarchical clustering method [CHCM; see Bendjoya & Zappala` defined as the average minimum distance between all neighbour- − 2002 and references therein], and the frequency hierarchical clus- ing asteroids in the (n, g, g s) domain, and I found a value of = −1 tering method (FHCM; Carruba & Michtchenko 2007, 2009).1 f 0 0.525 arcsec yr . Fig. 1 (panel B) displays the average num- In identifying asteroid families in the space of proper elements ber N 0, N min and the maximum number max (Ni)ofasteroidsas two parameters are fundamental: the cut-off distance at which the a function of the frequency cut-off defined by equation (2). The −1 value of Nmin corresponding at f 0 = 0.525 arcsec yr is 26. As family members are defined (d0) and the minimum number of ob- observed for the values of Nmin and max (Ni) obtained in the proper jects N min for a cluster to be considered significant. Beauge&Roig´ (2001) define a nominal distance cut-off as the average minimum element domain in the domain of frequencies, I still do not observe distance between all the neighbouring asteroids in the same region a much larger value of max Ni with respect to Nmin.Again,thismay suggest that the local background of the Phocaea family is indeed of the asteroid belt. The value of Nmin is defined by Zappalaetal.` (1995) as dominated by the Phocaea family itself (see Section 6). Since the Phocaea family is by far the most prominent family = + Nmin N0 2 N0, (1) in the region, I started by using the CHCM for this family. Fig. 2 (panel A) displays the number of family members (left ordinate) where N0 is the average number of orbits within a sphere of radius and the differential number dn/dv (right ordinate) as a function d0 at every point of the proper element space. A cluster with a number of objects larger than this critical value is called a clump, of the velocity cut-off. The red vertical line displays the nominal while a family is a cluster with a number of members larger than cut-off according to Beauge´ & Roig (2001). The numbers on the top of the peaks of differential asteroid numbers are related to the 2.5 × N min. As we shall see in more detail in Section 8, the region cluster of objects englobed by the Phocaea family.
Load more

Recommended publications
  • Dynamical Evolution of the Cybele Asteroids
    MNRAS 451, 244–256 (2015) doi:10.1093/mnras/stv997 Dynamical evolution of the Cybele asteroids Downloaded from https://academic.oup.com/mnras/article-abstract/451/1/244/1381346 by Universidade Estadual Paulista J�lio de Mesquita Filho user on 22 April 2019 V. Carruba,1‹ D. Nesvorny,´ 2 S. Aljbaae1 andM.E.Huaman1 1UNESP, Univ. Estadual Paulista, Grupo de dinamicaˆ Orbital e Planetologia, 12516-410 Guaratingueta,´ SP, Brazil 2Department of Space Studies, Southwest Research Institute, Boulder, CO 80302, USA Accepted 2015 May 1. Received 2015 May 1; in original form 2015 April 1 ABSTRACT The Cybele region, located between the 2J:-1A and 5J:-3A mean-motion resonances, is ad- jacent and exterior to the asteroid main belt. An increasing density of three-body resonances makes the region between the Cybele and Hilda populations dynamically unstable, so that the Cybele zone could be considered the last outpost of an extended main belt. The presence of binary asteroids with large primaries and small secondaries suggested that asteroid families should be found in this region, but only relatively recently the first dynamical groups were identified in this area. Among these, the Sylvia group has been proposed to be one of the oldest families in the extended main belt. In this work we identify families in the Cybele region in the context of the local dynamics and non-gravitational forces such as the Yarkovsky and stochastic Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effects. We confirm the detec- tion of the new Helga group at 3.65 au, which could extend the outer boundary of the Cybele region up to the 5J:-3A mean-motion resonance.
    [Show full text]
  • Color Changes for the Surface of 6478 Gault (??) Submitted to Apjl
    Draft version August 3, 2020 Typeset using LATEX twocolumn style in AASTeX63 Color changes for the Surface of 6478 Gault (??) 1 2 2 3 4 5 1 Remington Cantelas, Karen J. Meech, Jan T. Kleyna, Erica Bufanda, Alan Fitzsimmons, James Bauer, 2 2 2 6 2 2 Larry Denneau, Robert Weryk, Jacqueline V. Keane, Olivier R. Hainaut, and Richard J. Wainscoat 1 3 University of Central Florida, 4111 Libra Drive, Orlando, FL 32816, USA 2 4 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 3 5 Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 USA 4 6 Astrophysics Research Centre, Queen's University Belfast, Belfast BT7 1NN, UK 5 7 University of Maryland, Dept. of Astronomy, College Park, MD 20742-2421 USA 6 8 European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei M¨unchen,Germany 9 Submitted to ApJL 10 ABSTRACT 11 (6478) Gault is a main belt asteroid in the Phocaea Family which was discovered to have activity in 12 January 2019, and precovery images reveal it has been consistently active since at least September 2013. 13 Gault's activity is believed to be caused by it being a fast rotator near the asteroid break-up limit. We 14 have collected images and photometry from several telescopes dating back several apparitions. Using 15 this data we attempt to produce a reliable rotational light curve and confirm Gault's rotation period. 16 We also investigate possible color variations on the surface of the asteroid by measuring it's spectral 17 reflectivity over the course of 7 months between January and August 2019.
    [Show full text]
  • An Anisotropic Distribution of Spin Vectors in Asteroid Families
    Astronomy & Astrophysics manuscript no. families c ESO 2018 August 25, 2018 An anisotropic distribution of spin vectors in asteroid families J. Hanuš1∗, M. Brož1, J. Durechˇ 1, B. D. Warner2, J. Brinsfield3, R. Durkee4, D. Higgins5,R.A.Koff6, J. Oey7, F. Pilcher8, R. Stephens9, L. P. Strabla10, Q. Ulisse10, and R. Girelli10 1 Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovickáchˇ 2, 18000 Prague, Czech Republic ∗e-mail: [email protected] 2 Palmer Divide Observatory, 17995 Bakers Farm Rd., Colorado Springs, CO 80908, USA 3 Via Capote Observatory, Thousand Oaks, CA 91320, USA 4 Shed of Science Observatory, 5213 Washburn Ave. S, Minneapolis, MN 55410, USA 5 Hunters Hill Observatory, 7 Mawalan Street, Ngunnawal ACT 2913, Australia 6 980 Antelope Drive West, Bennett, CO 80102, USA 7 Kingsgrove, NSW, Australia 8 4438 Organ Mesa Loop, Las Cruces, NM 88011, USA 9 Center for Solar System Studies, 9302 Pittsburgh Ave, Suite 105, Rancho Cucamonga, CA 91730, USA 10 Observatory of Bassano Bresciano, via San Michele 4, Bassano Bresciano (BS), Italy Received x-x-2013 / Accepted x-x-2013 ABSTRACT Context. Current amount of ∼500 asteroid models derived from the disk-integrated photometry by the lightcurve inversion method allows us to study not only the spin-vector properties of the whole population of MBAs, but also of several individual collisional families. Aims. We create a data set of 152 asteroids that were identified by the HCM method as members of ten collisional families, among them are 31 newly derived unique models and 24 new models with well-constrained pole-ecliptic latitudes of the spin axes.
    [Show full text]
  • 1950 Da, 205, 269 1979 Va, 230 1991 Ry16, 183 1992 Kd, 61 1992
    Cambridge University Press 978-1-107-09684-4 — Asteroids Thomas H. Burbine Index More Information 356 Index 1950 DA, 205, 269 single scattering, 142, 143, 144, 145 1979 VA, 230 visual Bond, 7 1991 RY16, 183 visual geometric, 7, 27, 28, 163, 185, 189, 190, 1992 KD, 61 191, 192, 192, 253 1992 QB1, 233, 234 Alexandra, 59 1993 FW, 234 altitude, 49 1994 JR1, 239, 275 Alvarez, Luis, 258 1999 JU3, 61 Alvarez, Walter, 258 1999 RL95, 183 amino acid, 81 1999 RQ36, 61 ammonia, 223, 301 2000 DP107, 274, 304 amoeboid olivine aggregate, 83 2000 GD65, 205 Amor, 251 2001 QR322, 232 Amor group, 251 2003 EH1, 107 Anacostia, 179 2007 PA8, 207 Anand, Viswanathan, 62 2008 TC3, 264, 265 Angelina, 175 2010 JL88, 205 angrite, 87, 101, 110, 126, 168 2010 TK7, 231 Annefrank, 274, 275, 289 2011 QF99, 232 Antarctic Search for Meteorites (ANSMET), 71 2012 DA14, 108 Antarctica, 69–71 2012 VP113, 233, 244 aphelion, 30, 251 2013 TX68, 64 APL, 275, 292 2014 AA, 264, 265 Apohele group, 251 2014 RC, 205 Apollo, 179, 180, 251 Apollo group, 230, 251 absorption band, 135–6, 137–40, 145–50, Apollo mission, 129, 262, 299 163, 184 Apophis, 20, 269, 270 acapulcoite/ lodranite, 87, 90, 103, 110, 168, 285 Aquitania, 179 Achilles, 232 Arecibo Observatory, 206 achondrite, 84, 86, 116, 187 Aristarchus, 29 primitive, 84, 86, 103–4, 287 Asporina, 177 Adamcarolla, 62 asteroid chronology function, 262 Adeona family, 198 Asteroid Zoo, 54 Aeternitas, 177 Astraea, 53 Agnia family, 170, 198 Astronautica, 61 AKARI satellite, 192 Aten, 251 alabandite, 76, 101 Aten group, 251 Alauda family, 198 Atira, 251 albedo, 7, 21, 27, 185–6 Atira group, 251 Bond, 7, 8, 9, 28, 189 atmosphere, 1, 3, 8, 43, 66, 68, 265 geometric, 7 A- type, 163, 165, 167, 169, 170, 177–8, 192 356 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-09684-4 — Asteroids Thomas H.
    [Show full text]
  • Multiple Outbursts of Asteroid (6478) Gault∗
    Draft version March 14, 2019 Typeset using LATEX default style in AASTeX62 Multiple Outbursts of Asteroid (6478) Gault∗ 1, 2 3 4 5, 6, 5 Quanzhi Ye (叶泉志), Michael S. P. Kelley, Dennis Bodewits, Bryce Bolin, y Lynne Jones, Zhong-Yi Lin (林忠©),7 Eric C. Bellm,5 Richard Dekany,8 Dmitry A. Duev,1 Steven Groom,2 George Helou,2 Shrinivas R. Kulkarni,1 Thomas Kupfer,9 Frank J. Masci,2 Thomas A. Prince,1 and Maayane T. Soumagnac10 1Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, U.S.A. 2Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, U.S.A. 3Department of Astronomy, University of Maryland, College Park, MD 20742, U.S.A. 4Department of Physics, Auburn University, Auburn, AL 36849, U.S.A. 5DIRAC Institute, Department of Astronomy, University of Washington, 3910 15th Avenue NE, Seattle, WA 98195, U.S.A. 6B612 Asteroid Institute, 20 Sunnyside Ave, Suite 427, Mill Valley, CA 94941, U.S.A. 7Institute of Astronomy, National Central University, 32001, Taiwan 8Caltech Optical Observatories, California Institute of Technology, Pasadena, CA 91125, U.S.A. 9Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, U.S.A. 10Department of Particle Physics and Astrophysics, Weizmann Institute of Science 234 Herzl St., Rehovot, 76100, Israel (Received {; Revised {; Accepted {) Submitted to ApJL ABSTRACT Main-belt asteroid (6478) Gault unexpectedly sprouted two tails in late 2018 and early 2019, iden- tifying it as a new active asteroid. Here we present observations obtained by the 1.2-m Zwicky Tran- sient Facility survey telescope that provide detailed time-series coverage of the onset and evolution of Gault's activity.
    [Show full text]
  • Characterizing the Original Ejection Velocity Field of the Koronis Family
    ICARUS . ICARUS 00 (2021). 1–18 . Characterizing the original ejection velocity field of the Koronis family a,b, b a V. Carruba ∗, D. Nesvorn´y , S. Aljbaae aUniv. Estadual Paulista - UNESP, Grupo de Dinˆamica Orbital & Planetologia , Guaratinguet´a, CEP 12516-410 , SP , Brazil bDepartment of Space Studies, Southwest Space Research Institute, 1050 Walnut St.,Boulder, CO 80302, USA Abstract An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Un- fortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of the ejection velocity that is perpendicular to the orbital plane (vW ), may still be available, at least in part. In this work we estimate the magnitude of the original ejection velocity speeds of Koronis members using the observed distribution in proper eccentricity and inclination, and accounting for the spread caused by dynamical effects.
    [Show full text]
  • Asteroid Taxonomic Signatures from Photometric Phase Curves
    Asteroid taxonomic signatures from photometric phase curves D. A. Oszkiewicz1;2;3, E. Bowell2, L. H. Wasserman2, K. Muinonen1;4, A. Penttil¨a1, T. Pieniluoma1, D. E. Trilling3, C. A. Thomas3 1 Department of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland. 2 Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, U.S.A. 3 Department of Physics and Astronomy, Northern Arizona University, P.O. Box 6010, Flagstaff, AZ 86011, U.S.A. 4 Finnish Geodetic Institute, P.O. Box 15, FI-02431 Masala, Finland. Abstract We explore the correlation between an asteroid's taxonomy and photometric phase curve using the H;G12 photometric phase function, with the shape of the phase function described by the single parameter G12. We explore the usability of G12 in taxonomic classification for individual objects, asteroid families, and dynamical groups. We conclude that the mean values of G12 for the considered taxonomic complexes are statistically different, and also discuss the overall shape of the G12 distribution for each taxonomic complex. Based on the values of G12 for about half a million asteroids, we compute the probabilities of C, S, and X com- plex membership for each asteroid. For an individual asteroid, these probabilities are rather evenly distributed over all of the complexes, thus preventing meaning- ful classification. We then present and discuss the G12 distributions for asteroid families, and predict the taxonomic complex preponderance for asteroid families arXiv:1202.2270v1 [astro-ph.EP] 10 Feb 2012 given the distribution of G12 in each family. For certain asteroid families, the probabilistic prediction of taxonomic complex preponderance can clearly be made.
    [Show full text]
  • The Sporadic Activity of (6478) Gault: a YORP-Driven Event?
    The Astrophysical Journal Letters, 874:L20 (7pp), 2019 April 1 https://doi.org/10.3847/2041-8213/ab0f40 © 2019. The American Astronomical Society. All rights reserved. The Sporadic Activity of (6478) Gault: A YORP-driven Event? Jan T. Kleyna1 , Olivier R. Hainaut2 , Karen J. Meech1 , Henry H. Hsieh3,4 , Alan Fitzsimmons5 , Marco Micheli6,7 , Jacqueline V. Keane1 , Larry Denneau1 , John Tonry1 , Aren Heinze1 , Bhuwan C. Bhatt8 , Devendra K. Sahu8 , Detlef Koschny6,9,10 , Ken W. Smith5 , Harald Ebeling1 , Robert Weryk1 , Heather Flewelling1 , and Richard J. Wainscoat1 1 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 2 European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany 3 Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719, USA 4 Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan 5 Astrophysics Research Centre, Queen’s University Belfast, Belfast BT7 1NN, UK 6 ESA NEO Coordination Centre, Largo Galileo Galilei, 1, I-00044 Frascati (RM), Italy 7 INAF—Osservatorio Astronomico di Roma, Via Frascati, 33, I-00040 Monte Porzio Catone (RM), Italy 8 Indian Institute for Astrophysics, II Block, Koramangala, Bangalore 560 034, India 9 ESTEC, European Space Agency, Keplerlaan 1, 2201 AZ, Noordwijk, The Netherlands 10 Chair of Astronautics, Technical University of Munich, Boltzmannstraße 15, D-85748 Garching bei München, Germany Received 2019 February 22; revised 2019 March 13; accepted 2019 March 13; published 2019 April 1 Abstract On 2019 January 5 a streamer associated with the 4–10 km main belt asteroid (6478)Gault was detected by the ATLAS sky survey, a rare discovery of activity around a main belt asteroid.
    [Show full text]
  • Asteroid Belt - Wikipedia
    12/2/2018 Asteroid belt - Wikipedia Asteroid belt The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets. The asteroid belt is also termed the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids.[1] About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea.[1] The total mass of the asteroid belt is approximately 4% that of the Moon, or 22% that of Pluto, and roughly twice that of Pluto's moon Charon (whose diameter is 1200 km). Ceres, the asteroid belt's only dwarf planet, is about 950 km in diameter, whereas 4 Vesta, 2 Pallas, and 10 Hygiea have mean diameters of less than 600 km.[2][3][4][5] The remaining bodies range down to the size of a dust particle. The asteroid material is so thinly distributed that numerous unmanned spacecraft have traversed it without incident.[6] Nonetheless, collisions between large asteroids do occur, and these can produce an asteroid family whose members have similar orbital characteristics and compositions. Individual asteroids within the asteroid belt are categorized by their spectra, with most falling into three basic groups: carbonaceous (C-type), silicate (S-type), and metal-rich (M-type). The asteroid belt formed from the primordial solar nebula as a group of planetesimals.[7] Planetesimals are the The asteroids of the inner Solar System and Jupiter: The donut-shaped asteroid belt is located smaller precursors of the protoplanets.
    [Show full text]
  • Synthetic Tracking Using ZTF Deep Drilling Data Sets Chengxing Zhai1 , Quanzhi Ye2,3,4, Michael Shao1, Russell Trahan1, Navtej S
    Publications of the Astronomical Society of the Pacific, 132:064502 (8pp), 2020 June https://doi.org/10.1088/1538-3873/ab828b © 2020. The Astronomical Society of the Pacific Printed in the U.S.A. Synthetic Tracking Using ZTF Deep Drilling Data Sets Chengxing Zhai1 , Quanzhi Ye2,3,4, Michael Shao1, Russell Trahan1, Navtej S. Saini1, Janice Shen1, Thomas A. Prince2, Eric C. Bellm5, Matthew J. Graham2 , George Helou3, Shrinivas R. Kulkarni2, Thomas Kupfer6, Russ R. Laher3, Ashish Mahabal2,3 , Frank J. Masci3 , Ben Rusholme3, Philippe Rosnet7, and David L. Shupe3 1 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109, USA; [email protected] 2 Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 3 IPAC, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA 4 University of Maryland, Department of Astronomy, College Park, MD 20742, USA 5 DIRAC Institute, Department of Astronomy, University of Washington, 3910 15th Avenue NE, Seattle, WA 98195, USA 6 Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA 7 Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France Received 2020 January 13; accepted 2020 March 23; published 2020 April 21 Abstract The Zwicky Transit Facility (ZTF) is a powerful time domain survey telescope with a large field of view of 47 deg2. We apply the synthetic tracking technique to integrate a ZTF’s deep drilling data set, which consists of 133 nominal 30 s exposure frames spanning about 1.5 hr, to search for slowly moving asteroids down to approximately 23rd magnitude.
    [Show full text]
  • Prezentácia Programu Powerpoint
    VÝSKUM ASTEROIDOV A KOMÉT NA ASTRONOMICKOM ÚSTAVE SAV MAREK HUSÁRIK ASTRONOMICKÝ ÚSTAV SAV, T. LOMNICA BEZOVEC 2020 2. OKTÓBER BRIEF HISTORY OF COMET AND ASTEROID RESEARCH • 1943 – starting of comet discoveries and meteor research • 1946 – discovery of the first comet Pajdušáková-Rotbart-Weber • 1946-1959 – 70 new comets discovered over the world, 18 from Skalnate Pleso (Honda- Mrkos-Pajdušáková, Tuttle-Giacobini-Kresák, 1957 V Mrkos,...) • 1964 – asteroid observations and astrometry CURRENT RESEARCH AT THE INTERPLANETARY MATTER DEPARTMENT • Investigation of the activity, physical and dynamical evolution of selected cometary nuclei • Color photometry, lightcurves, and modelling of shapes of the asteroids • Study of transfer orbits, interrelations and evolution among different populations regarding near- Earth objects • Study of the structure of the outer part of the Oort cloud and the Edgeworth-Kuiper belt • Study of structure and dynamics of meteoroid streams, evolution of their parent bodies, the distribution of meteoroid particles in the inner Solar System, search for meteoroid streams of asteroidal origin, search for hyperbolic and interstellar meteoroids • Operation of the all-sky bolide cameras within the European Fireball Network • Study of meteorite properties • Study of the physical and chemical properties of asteroid/comet surfaces and their relevant terrestrial analogs, simulation of effects of space weathering in laboratory conditions • The IAU Meteor Data Center (MDC) operates at the AI SAS under the auspices of Division F (Planetary Systems and Bioastronomy) of the International Astronomical Union (IAU). The MDC is responsible for the designation of meteor showers, for the efficient collection, (computation,) checking and dissemination of trajectory observations and orbits of meteors. It acts as a central depository for meteor orbits obtained by photographic, video and radar techniques.
    [Show full text]
  • Astronomy Quiz
    Aryabhat Astronomy Quiz Study Material Part 1 The Sun Our Sun (called Sol by the Romans from which we get the word solar) is a main sequence G2 dwarf star. This means that it is fusing hydrogen into helium as its main power source, and that its mass is such that it emits its most intense light at a yellow frequency at about 5800 degrees Kelvin (a G2 star). The Sun is a micro variable star. We used to think that the Sun was a constant star, but we have learned that every star is variable to some degree. The Sun has an absolute magnitude of 4.8 at the standard distance of 10 parsecs (2062648 AUs). This compares to an apparent magnitude -26.7 at 1 AU (8.3 light minutes). Of the hundred nearest stars only three Sirius, Alpha Centauri 1&2 are larger. Alpha Eridani is almost as large and then stars get small fast. Most are faint red dwarfs. The Sun has many features, which have no counterpart in the planets. Here are some of these features: The Sun emits a thin solar wind of particles driven from the Sun's surface by light pressure, electrical charges or magnetic fluxes. This solar wind can be detected throughout the solar system. In large planets, when these solar winds interact with the magnetic field of the planet, auroras are caused. The Sun's corona is its very fragile outermost atmosphere, an extremely hot gas which is in the millions of degrees. We normally do not see this gas, but during eclipses these pale outer atmosphere creates strange flame like images much larger than the Sun's disk.
    [Show full text]