Radar and photometric observations and shape modeling of contact binary near-Earth Asteroid (8567) 1996 HW1

    Authors

    C. Magri; E. S. Howell; M. C. Nolan; P. A. Taylor; Y. R. Fernandez; M. Mueller; R. J. Vervack; L. A. M. Benner; J. D. Giorgini; S. J. Ostro; D. J. Scheeres; M. D. Hicks; H. Rhoades; J. M. Somers; N. M. Gaftonyuk; V. V. Kouprianov; Y. N. Krugly; I. E. Molotov; M. W. Busch; J. L. Margot; V. Benishek; V. Protitch-Benishek; A. Galad; D. Higgins; P. Kusnirak;D. P. Pray

    Comments

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    Abbreviated Journal Title

    Icarus

    Keywords

    Asteroids; Photometry; Radar observations; 4769 CASTALIA; LIGHTCURVE INVERSION; OPTIMIZATION METHODS; PHYSICAL; MODEL; YORP; POPULATION; EVOLUTION; ITOKAWA; IMAGES; KW4; Astronomy & Astrophysics

    Abstract

    We observed near-Earth Asteroid (8567) 1996 HW1 at the Arecibo Observatory on six dates in September 2008, obtaining radar images and spectra. By combining these data with an extensive set of new lightcurves taken during 2008-2009 and with previously published lightcurves from 2005, we were able to reconstruct the object's shape and spin state. 1996 HW1 is an elongated, bifurcated object with maximum diameters of 3.8 x 1.6 x 1.5 km and a contact-binary shape. It is the most bifurcated near-Earth asteroid yet studied and one of the most elongated as well. The sidereal rotation period is 8.76243 +/- 0.00004 h and the pole direction is within 50 of ecliptic longitude and latitude (281 degrees, -31 degrees). Radar astrometry has reduced the orbital element uncertainties by 27% relative to the a priori orbit solution that was based on a half-century of optical data. Simple dynamical arguments are used to demonstrate that this asteroid could have originated as a binary system that tidally decayed and merged. (C) 2011 Elsevier Inc. All rights reserved.

    Journal Title

    Icarus

    Volume

    214

    Issue/Number

    1

    Publication Date

    1-1-2011

    Document Type

    Article

    Language

    English

    First Page

    210

    Last Page

    227

    WOS Identifier

    WOS:000292853600015

    ISSN

    0019-1035

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