Photometric survey of binary near-Earth asteroids

Autor: J. Zhu, Z. Krzeminski, Štefan Gajdoš, Michael D. Hicks, A. Klotz, B. L. Knight, R. R. Dyvig, Peter Brown, M. Grenon, Yu. N. Krugly, Robert D. Stephens, Walter R. Cooney, Y. Revaz, Jozef Vilagi, P. Scheirich, A. Grauer, Raoul Behrend, Franck Marchis, Lenka Šarounová, Peter Kusnirak, Stefano Mottola, Robert J. Whiteley, Gianluca Masi, G. Burki, Alan W. Harris, Ellen S. Howell, V. Cotrez, C. Demeautis, Jean-Luc Margot, Petr Pravec, N. Waelchli, David J. Tholen, Stephen Larson, Donald P. Pray, Vishnu Reddy, L. Brunetto, S. Moore, P. Thierry, D. Matter, Michael C. Nolan, G. Esquerdo, K. Kirsch, G. M. Funkhouser, G. Kober, G. Hahn, W. Holliday, Brian D. Warner, D. R. Degraff, F. P. Velichko, Adrian Galad, David Higgins, M. Rieugné, Lance A. M. Benner, L. Snyder, R. Roy, S. M. Slivan, N. Kaiser
Přispěvatelé: Astronomical Institute of the Czech Academy of Sciences (ASU / CAS), Czech Academy of Sciences [Prague] (CAS), DLR Institute of Planetary Research, Rutherfordstr. 2, D-12489 Berlin, Germany, Department of Physics and Astronomy, University of Western Ontario, Carbuncle Hill Observatory, Palmer Divide Observatory, Colorado Springs, Space Science Institute, La Canada, National Astronomy and Ionosphere Center / Arecibo Observatory, HC3 Box 53995, Arecibo (NAIC), Jet Propulsion Laboratory, California Institute of Technology (JPL), Department of Astronomy, Cornell University, Ithaca, NY 14853, USA, Modra Observatory, Department of Astronomy, Physics of the Earth and Meteorology, River Oaks Observatory, 1125 Isaac Creek Circle, New Braunfels, TX 78132, USA, Institute of Astronomy [Kharkiv], V.N. Karazin Kharkiv National University (KhNU), Institute for Astronomy, University of Hawaii, Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Department of Astronomy, University of California, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Alfred University, Department of Physics and Astronomy, University of Arkansas, United States Naval Observatory (USNO), Beijing Astronomical Observatory, Chinese Academy of Sciences, Badlands Observatory, Keck Observatoires, University of North Dakota, Astronomy Department, California Institute of Technology, Pasadena, Università degli Studi di Roma Tor Vergata [Roma], Campo Catino Observatory, Hunters Hill Observatory, Department of Astronomy, Whitin Observatory, Wellesley College, Observatoire de Genève, Observatoire de Blauvac, 138 Village-Neuf, F.-X. Bagnoud Observatory, CH-3961 St-Luc, Switzerland, Observatoire d'astronomie de Saint-Caprais, Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Le Cres Observatory, Observatoire N°139 d'Antibes
Rok vydání: 2006
Předmět:
Zdroj: Icarus
Icarus, 2006, 181, pp.63-93. ⟨10.1016/j.icarus.2005.10.014⟩
ISSN: 0019-1035
1090-2643
Popis: Photometric data on 17 binary near-Earth asteroids (15 of them are certain detections, two are probables) were analysed and characteristic properties of the near-Earth asteroid (NEA) binary population were inferred. We have found that binary systems with a secondary-to-primary mean diameter ratio D s / D p ⩾ 0.18 concentrate among NEAs smaller than 2 km in diameter; the abundance of such binaries decreases significantly among larger NEAs. Secondaries show an upper size limit of D s = 0.5 – 1 km . Systems with D s / D p ⩽ 0.5 are abundant but larger satellites are significantly less common. Primaries have spheroidal shapes and they rotate rapidly, with periods concentrating between 2.2 to 2.8 h and with a tail of the distribution up to ∼4 h. The fast rotators are close to the critical spin for rubble piles with bulk densities about 2 g/cm3. Orbital periods show an apparent cut-off at P orb ∼ 11 h ; closer systems with shorter orbital periods have not been discovered, which is consistent with the Roche limit for strengthless bodies. Secondaries are more elongated on average than primaries. Most, but not all, of their rotations appear to be synchronized with the orbital motion; nonsynchronous secondary rotations may occur especially among wider systems with P orb > 20 h. The specific total angular momentum of most of the binary systems is similar to within ±20% and close to the angular momentum of a sphere with the same total mass and density, rotating at the disruption limit; this suggests that the binaries were created by mechanism(s) related to rotation near the critical limit and that they neither gained nor lost significant amounts of angular momentum during or since formation. A comparison with six small asynchronous binaries detected in the main belt of asteroids suggests that the population extends beyond the region of terrestrial planets, but with characteristics shifted to larger sizes and longer periods. The estimated mean proportion of binaries with D s / D p ⩾ 0.18 among NEAs larger than 0.3 km is 15 ± 4 % . Among fastest rotating NEAs larger than 0.3 km with periods between 2.2 and 2.8 h, the mean proportion of such binaries is (66+10−12)%.
Databáze: OpenAIRE
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