Shape and Spin Determination of Barbarian Asteroids? M
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A Successful Search for Hidden Barbarians in the Watsonia Asteroid
MNRASL 439, L75–L79 (2014) doi:10.1093/mnrasl/slt184 Advance Access publication 2014 January 16 A successful search for hidden Barbarians in the Watsonia asteroid family A. Cellino,1† S. Bagnulo,2 P. Tanga, 3 B. Novakovic´4 and M. Delbo`3 1INAF – Osservatorio Astrofisico di Torino, I-10025 Pino Torinese, Italy 2Armagh Observatory, College Hill, Armagh BT61 9DG, UK 3University of Nice Sophia Antipolis, CNRS, Observatoire de la Coteˆ d’Azur, Laboratoire Cassiopee,´ France 4Department of Astronomy, Faculty of Mathematics, University of Belgrade, RS-11000 Belgrade, Serbia Downloaded from https://academic.oup.com/mnrasl/article/439/1/L75/1029760 by guest on 07 October 2020 Accepted 2013 December 20. Received 2013 December 20; in original form 2013 October 15 ABSTRACT Barbarians, so named after the prototype of this class (234) Barbara, are a rare class of asteroids exhibiting anomalous polarimetric properties. Their very distinctive feature is that they show negative polarization at relatively large phase angles, where all ‘normal’ asteroids show positive polarization. The origin of the Barbarian phenomenon is unclear, but it seems to be correlated with the presence of anomalous abundances of spinel, a mineral usually associated with the so-called calcium–aluminium-rich inclusions (CAIs) on meteorites. Since CAIs are samples of the oldest solid matter identified in our Solar system, Barbarians are very interesting targets for investigations. Inspired by the fact that some of the few known Barbarians are members of, or very close to, the dynamical family of Watsonia, we have checked whether this family is a major repository of Barbarians, in order to obtain some hints about their possible collisional origin. -
Photometry of Asteroids: Lightcurves of 24 Asteroids Obtained in 1993–2005
ARTICLE IN PRESS Planetary and Space Science 55 (2007) 986–997 www.elsevier.com/locate/pss Photometry of asteroids: Lightcurves of 24 asteroids obtained in 1993–2005 V.G. Chiornya,b,Ã, V.G. Shevchenkoa, Yu.N. Kruglya,b, F.P. Velichkoa, N.M. Gaftonyukc aInstitute of Astronomy of Kharkiv National University, Sumska str. 35, 61022 Kharkiv, Ukraine bMain Astronomical Observatory, NASU, Zabolotny str. 27, Kyiv 03680, Ukraine cCrimean Astrophysical Observatory, Crimea, 98680 Simeiz, Ukraine Received 19 May 2006; received in revised form 23 December 2006; accepted 10 January 2007 Available online 21 January 2007 Abstract The results of 1993–2005 photometric observations for 24 main-belt asteroids: 24 Themis, 51 Nemausa, 89 Julia, 205 Martha, 225 Henrietta, 387 Aquitania, 423 Diotima, 505 Cava, 522 Helga, 543 Charlotte, 663 Gerlinde, 670 Ottegebe, 693 Zerbinetta, 694 Ekard, 713 Luscinia, 800 Kressmania, 1251 Hedera, 1369 Ostanina, 1427 Ruvuma, 1796 Riga, 2771 Polzunov, 4908 Ward, 6587 Brassens and 16541 1991 PW18 are presented. The rotation periods of nine of these asteroids have been determined for the first time and others have been improved. r 2007 Elsevier Ltd. All rights reserved. Keywords: Asteroids; Photometry; Lightcurve; Rotational period; Amplitude 1. Introduction telescope of the Crimean Astrophysics Observatory in Simeiz. Ground-based observations are the main source of knowledge about the physical properties of the asteroid 2. Observations and their reduction population. The photometric lightcurves are used to determine rotation periods, pole coordinates, sizes and Photometric observations of the asteroids were carried shapes of asteroids, as well as to study the magnitude-phase out in 1993–1994 using one-channel photoelectric photo- relation of different type asteroids. -
The Minor Planet Bulletin
THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 36, NUMBER 3, A.D. 2009 JULY-SEPTEMBER 77. PHOTOMETRIC MEASUREMENTS OF 343 OSTARA Our data can be obtained from http://www.uwec.edu/physics/ AND OTHER ASTEROIDS AT HOBBS OBSERVATORY asteroid/. Lyle Ford, George Stecher, Kayla Lorenzen, and Cole Cook Acknowledgements Department of Physics and Astronomy University of Wisconsin-Eau Claire We thank the Theodore Dunham Fund for Astrophysics, the Eau Claire, WI 54702-4004 National Science Foundation (award number 0519006), the [email protected] University of Wisconsin-Eau Claire Office of Research and Sponsored Programs, and the University of Wisconsin-Eau Claire (Received: 2009 Feb 11) Blugold Fellow and McNair programs for financial support. References We observed 343 Ostara on 2008 October 4 and obtained R and V standard magnitudes. The period was Binzel, R.P. (1987). “A Photoelectric Survey of 130 Asteroids”, found to be significantly greater than the previously Icarus 72, 135-208. reported value of 6.42 hours. Measurements of 2660 Wasserman and (17010) 1999 CQ72 made on 2008 Stecher, G.J., Ford, L.A., and Elbert, J.D. (1999). “Equipping a March 25 are also reported. 0.6 Meter Alt-Azimuth Telescope for Photometry”, IAPPP Comm, 76, 68-74. We made R band and V band photometric measurements of 343 Warner, B.D. (2006). A Practical Guide to Lightcurve Photometry Ostara on 2008 October 4 using the 0.6 m “Air Force” Telescope and Analysis. Springer, New York, NY. located at Hobbs Observatory (MPC code 750) near Fall Creek, Wisconsin. -
New Cases of Unusual Polarimetric Behavior in Asteroids
A&A 482, 309–314 (2008) Astronomy DOI: 10.1051/0004-6361:20078965 & c ESO 2008 Astrophysics New cases of unusual polarimetric behavior in asteroids R. Gil-Hutton1,2, V. Mesa2, A. Cellino3, P. Bendjoya4, L. Peñaloza2,andF.Lovos2 1 Complejo Astronómico El Leoncito – CONICET, Av. España 1512 sur, J5402DSP San Juan, Argentina e-mail: [email protected] 2 Universidad Nacional de San Juan, J. I. de la Roza 590 oeste, 5400 Rivadavia, San Juan, Argentina 3 INAF, Osservatorio Astronomico di Torino, 10025 Pino Torinese (TO), Italy 4 Laboratoire Fizeau, UMR 6525 Université Nice Sophia Antipolis , Observatoire de la Côte d’Azur, CNRS, 06108 Nice Cedex 2, France Received 30 October 2007 / Accepted 5 February 2008 ABSTRACT Aims. Results of different polarimetric campaigns at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina are presented. The aim of these campaigns was to search for objects exhibiting anomalous polarimetric properties, similar to those shown by the Ld-class asteroid (234) Barbara, among members of the same or similar taxonomic classes. Methods. The data have been obtained with Torino and CASPROF polarimeters at the 2.15 m telescope. The Torino polarimeter is an instrument that allows simultaneous measurement of polarization in five different bands, and CASPROF polarimeter is a two-hole aperture polarimeter with rapid modulation. Results. The campaigns began in 2005, and we found four new asteroids with Barbara-like polarimetric properties: the L-class objects (172) Baucis, (236) Honoria and (980) Anacostia, and the K-class asteroid (679) Pax. The polarimetric properties of the phase-polarization curves of these objects may be produced by a mixture of high- and low-albedo particles in their regolith as a result of the fragmentation of a substrate that is spectrally analog to the CO3/CV3 chondrites. -
Year XIX, Supplement Ethnographic Study And/Or a Theoretical Survey of a Their Position in the Article Should Be Clearly Indicated
III. TITLES OF ARTICLES DRU[TVO ANTROPOLOGOV SLOVENIJE The journal of the Slovene Anthropological Society Titles (in English and Slovene) must be short, informa- SLOVENE ANTHROPOLOGICAL SOCIETY Anthropological Notebooks welcomes the submis- tive, and understandable. The title should be followed sion of papers from the field of anthropology and by the name of the author(s), their position, institutional related disciplines. Submissions are considered for affiliation, and if possible, by e-mail address. publication on the understanding that the paper is not currently under consideration for publication IV. ABSTRACT AND KEYWORDS elsewhere. It is the responsibility of the author to The abstract must give concise information about the obtain permission for using any previously published objective, the method used, the results obtained, and material. Please submit your manuscript as an e-mail the conclusions. Authors are asked to enclose in English attachment on [email protected] and enclose your contact information: name, position, and Slovene an abstract of 100 – 200 words followed institutional affiliation, address, phone number, and by three to five keywords. They must reflect the field of e-mail address. research covered in the article. English abstract should be placed at the beginning of an article and the Slovene one after the references at the end. V. NOTES A N T H R O P O L O G I C A L INSTRUCTIONS Notes should also be double-spaced and used sparingly. They must be numbered consecutively throughout the text and assembled at the end of the article just before references. VI. QUOTATIONS Short quotations (less than 30 words) should be placed in single quotation marks with double marks for quotations within quotations. -
The Minor Planet Bulletin 44 (2017) 142
THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 44, NUMBER 2, A.D. 2017 APRIL-JUNE 87. 319 LEONA AND 341 CALIFORNIA – Lightcurves from all sessions are then composited with no TWO VERY SLOWLY ROTATING ASTEROIDS adjustment of instrumental magnitudes. A search should be made for possible tumbling behavior. This is revealed whenever Frederick Pilcher successive rotational cycles show significant variation, and Organ Mesa Observatory (G50) quantified with simultaneous 2 period software. In addition, it is 4438 Organ Mesa Loop useful to obtain a small number of all-night sessions for each Las Cruces, NM 88011 USA object near opposition to look for possible small amplitude short [email protected] period variations. Lorenzo Franco Observations to obtain the data used in this paper were made at the Balzaretto Observatory (A81) Organ Mesa Observatory with a 0.35-meter Meade LX200 GPS Rome, ITALY Schmidt-Cassegrain (SCT) and SBIG STL-1001E CCD. Exposures were 60 seconds, unguided, with a clear filter. All Petr Pravec measurements were calibrated from CMC15 r’ values to Cousins Astronomical Institute R magnitudes for solar colored field stars. Photometric Academy of Sciences of the Czech Republic measurement is with MPO Canopus software. To reduce the Fricova 1, CZ-25165 number of points on the lightcurves and make them easier to read, Ondrejov, CZECH REPUBLIC data points on all lightcurves constructed with MPO Canopus software have been binned in sets of 3 with a maximum time (Received: 2016 Dec 20) difference of 5 minutes between points in each bin. -
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1,. ,-- ,-- ~XECKDING PAGE BLANK WT FIL,,q DYNAMICAL EVIDENCE REGARDING THE RELATIONSHIP BETWEEN ASTEROIDS AND METEORITES GEORGE W. WETHERILL Department of Temcltricrl kgnetism ~amregie~mtittition of Washington Washington, D. C. 20025 Meteorites are fragments of small solar system bodies (comets, asteroids and Apollo objects). Therefore they may be expected to provide valuable information regarding these bodies. How- ever, the identification of particular classes of meteorites with particular small bodies or classes of small bodies is at present uncertain. It is very unlikely that any significant quantity of meteoritic material is obtained from typical ac- tive comets. Relatively we1 1-studied dynamical mechanisms exist for transferring material into the vicinity of the Earth from the inner edge of the asteroid belt on an 210~-~year time scale. It seems likely that most iron meteorites are obtained in this way, and a significant yield of complementary differec- tiated meteoritic silicate material may be expected to accom- pany these differentiated iron meteorites. Insofar as data exist, photometric measurements support an association between Apollo objects and chondri tic meteorites. Because Apol lo ob- jects are in orbits which come close to the Earth, and also must be fragmented as they traverse the asteroid belt near aphel ion, there also must be a component of the meteorite flux derived from Apollo objects. Dynamical arguments favor the hypothesis that most Apollo objects are devolatilized comet resiaues. However, plausible dynamical , petrographic, and cosmogonical reasons are known which argue against the simple conclusion of this syllogism, uiz., that chondri tes are of cometary origin. Suggestions are given for future theoretical , observational, experimental investigations directed toward improving our understanding of this puzzling situation. -
Volumes and Bulk Densities of Forty Asteroids from ADAM Shape Modeling
Astronomy & Astrophysics manuscript no. ADAM_all c ESO 2017 February 8, 2017 Volumes and bulk densities of forty asteroids from ADAM shape modeling J. Hanuš1; 2; 3∗, M. Viikinkoski4, F. Marchis5, J. Durechˇ 3, M. Kaasalainen4, M. Delbo’2, D. Herald6, E. Frappa7, T. Hayamizu8, S. Kerr9, S. Preston9, B. Timerson9, D. Dunham9, and J. Talbot10 1 Centre National d’Études Spatiales, 2 place Maurice Quentin, 75039 Paris cedex 01, France ∗e-mail: [email protected] 2 Université Côte d’Azur, OCA, CNRS, Lagrange, France 3 Astronomical Institute, Faculty of Mathematics and Physics, Charles University, V Holešovickáchˇ 2, 18000 Prague, Czech Re- public 4 Department of Mathematics, Tampere University of Technology, PO Box 553, 33101, Tampere, Finland 5 SETI Institute, Carl Sagan Center, 189 Bernado Avenue, Mountain View CA 94043, USA 6 RASNZ Occultation Section, 3 Lupin Pl., Murrumbateman, NSW 2582, Australia 7 Euraster, 8 route de Soulomes, 46240 Labastide-Murat, France 8 JOIN / Japan Occultation Infomation Network 9 International Occultation Timing Association (IOTA) 10 RASNZ Occultation Section, 3 Hughes Street, Waikanae Beach, Kapiti Coast, 5036, New Zealand Received x-x-2016 / Accepted x-x-2016 ABSTRACT Context. Disk-integrated photometric data of asteroids do not contain accurate information on shape details or size scale. Additional data such as disk-resolved images or stellar occultation measurements further constrain asteroid shapes and allow size estimates. Aims. We aim to use all available disk-resolved images of about forty asteroids obtained by the Near-InfraRed Camera (Nirc2) mounted on the W.M. Keck II telescope together with the disk-integrated photometry and stellar occultation measurements to deter- mine their volumes. -
Cosmic History and a Candidate Parent Asteroid for the Quasicrystal-Bearing Meteorite Khatyrka
COSMIC HISTORY AND A CANDIDATE PARENT ASTEROID FOR THE QUASICRYSTAL-BEARING METEORITE KHATYRKA Matthias M. M. Meier1*, Luca Bindi2,3, Philipp R. Heck4, April I. Neander5, Nicole H. Spring6,7, My E. I. Riebe1,8, Colin Maden1, Heinrich Baur1, Paul J. Steinhardt9, Rainer Wieler1 and Henner Busemann1 1Institute of Geochemistry and Petrology, ETH Zurich, Zurich, Switzerland. 2Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy. 3CNR-Istituto di Geoscienze e Georisorse, Sezione di Firenze, Florence, Italy. 4Robert A. Pritzker Center for Meteoritics and Polar Studies, Field Museum of Natural History, Chicago, USA. 5De- partment of Organismal Biology and Anatomy, University of Chicago, Chicago, USA. 6School of Earth and Environ- mental Sciences, University of Manchester, Manchester, UK. 7Department of Earth and Atmospheric Sciences, Uni- versity of Alberta, Edmonton, Canada. 8Current address: Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, USA. 9Department of Physics, and Princeton Center for Theoretical Science, Princeton University, Princeton, USA. *corresponding author: [email protected]; (office phone: +41 44 632 64 53) Submitted to Earth and Planetary Science Letters. Abstract The unique CV-type meteorite Khatyrka is the only natural sample in which “quasicrystals” and associated crystalline Cu,Al-alloys, including khatyrkite and cupalite, have been found. They are suspected to have formed in the early Solar System. To better understand the origin of these ex- otic phases, and the relationship of Khatyrka to other CV chondrites, we have measured He and Ne in six individual, ~40-μm-sized olivine grains from Khatyrka. We find a cosmic-ray exposure age of about 2-4 Ma (if the meteoroid was <3 m in diameter, more if it was larger). -
Astrophysical Light Scattering Problems (PAP316)
Astrophysical light scattering problems (PAP316) Lecture 7a Karri Muinonen1,2 Professor of Astronomy 1Department of Physics, University of Helsinki, Finland 2Finnish Geospatial Research Institute (FGI), Masala, Finland Contents • Introduction • Asteroids – Polarimetry, photometry, spectrometry – Polarimetric data – Telescopes and instruments – Interpretation of data – Polarization vs. taxonomy – Properties of F-class asteroids – Barbarians – Wavelength dependence – Near-Earth asteroids – Space weathering phenomena – Comparison of albedos – Open problems – Polarimetry in asteroid science – Subjects for future investigation • Intermediate conclusions Introduction • Physical characterization of astronomical objects (e.g., surfaces of airless planetary objects) • Direct problem of light scattering by particles with varying particle size, shape, refractive index, and spatial distribution • Inverse problem based on astronomical observations and/or experimental measurements • Plane of scattering, scattering angle, solar phase angle, degree of linear polarization Asteroids Photometry Polarimetry Muinonen et al., in Polarimetry of Stars and Planetary Systems, 2016 (obs. ref. therein) Polarimetric data • Disk-integrated observations only • Asteroid Polarimetric Database • (1) Ceres most extensively observed • Main-belt, near- Earth, transneptunian objects Telescopes and instruments • Crimean • Nice Observatory in Astrophysical Calern with Torino Observatory (UBVRI Observatory polarimeter by • University of Hawaii, Vilppu Piirola) Mauna Kea • Complejo -