Photometric survey of binary near-Earth asteroids

P. Pravec (1) , Peter Scheirich (1) , P. Kusnirak (1) , L. Sarounová (1) , Stefano Mottola (2) , G. Hahn (2) , P. Brown (3) , G. Esquerdo (3) , N. Kaiser (3) , Z. Krzeminski (3) , D. P. Pray (4) , Brian D. Warner (5) , Alan W. Harris (6) , Michael C. Nolan (7) , Ellen S. Howell (7) , Lance A. M. Benner (8) , Jean-Luc Margot (9) , Adrián Galád (1, 10) , W. Holliday (11) , Michael D. Hicks (8) , Yurij N. Krugly (12) , David J. Tholen (13) , R. J. Whiteley (14) , Franck Marchis (15, 16, 17) , D. R. Degraff (18) , A. Grauer (19) , S. Larson (14) , F. P. Velichko (12) , W. R. Cooney (20) , R. Stephens (20) , J. Zhu (21) , K. Kirsch (22) , R. Dyvig (22) , L. Snyder (23) , V. Reddy (24) , S. A. Moore (25) , Stefan Gajdos (10) , Jozef Világi (10) , G. Masi (26, 27) , D. Higgins (28) , G. Funkhouser (29) , B. Knight (29) , S. Slivan (29) , Raoul Behrend (30) , M. Grenon (30) , G. Burki (30) , R. Roy (31) , C. Demeautis (32) , D. Matter (32) , N. Waelchli (33) , Yves Revaz (33) , Alain Klotz (34, 35) , M. Rieugné (34) , P. Thierry (34) , V. Cotrez (36) , L. Brunetto (37) , G. Kober (37)

1 ASU / CAS - Astronomical Institute of the Czech Academy of Sciences
2 DLR Institute of Planetary Research
3 UWO - University of Western Ontario
4 Carbuncle Hill Observatory
5 Palmer Divide Observatory, Colorado Springs
6 Space Science Institute, La Canada
7 NAIC - National Astronomy and Ionosphere Center / Arecibo Observatory, HC3 Box 53995, Arecibo
8 JPL - Jet Propulsion Laboratory
9 Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
10 Modra Observatory, Department of Astronomy, Physics of the Earth and Meteorology
11 River Oaks Observatory, 1125 Isaac Creek Circle, New Braunfels, TX 78132, USA
12 Institute of Astronomy [Kharkiv]
13 Institute for Astronomy, University of Hawaii
14 LPL - Lunar and Planetary Laboratory [University of Arizona]
15 Department of Astronomy, University of California
16 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
17 GAP - Groupe Astrométrie et Planétologie
18 Alfred University
19 Department of Physics and Astronomy, University of Arkansas
20 USNO - United States Naval Observatory
21 Beijing Astronomical Observatory, Chinese Academy of Sciences
22 Badlands Observatory
23 Keck Observatoires
24 University of North Dakota
25 Astronomy Department, California Institute of Technology, Pasadena
26 Università degli Studi di Roma Tor Vergata [Roma] = University of Rome Tor Vergata
27 Campo Catino Observatory
28 Hunters Hill Observatory
29 Department of Astronomy, Whitin Observatory, Wellesley College
30 Observatoire de Genève
31 Observatoire de Blauvac
32 138 Village-Neuf
33 F.-X. Bagnoud Observatory, CH-3961 St-Luc, Switzerland
34 Observatoire d'astronomie de Saint-Caprais
35 OHP - Observatoire de Haute-Provence
36 Le Cres Observatory
37 Observatoire N°139 d'Antibes

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/D=>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=0.5-1 km. Systems with D/D20 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/D=>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)%.

Domaines: Astrophysique [astro-ph]

P. Pravec, Peter Scheirich, P. Kusnirak, L. Sarounová, Stefano Mottola, et al.. Photometric survey of binary near-Earth asteroids. Icarus, 2006, 181, pp.63-93. ⟨10.1016/j.icarus.2005.10.014⟩. ⟨hal-03692201⟩