@article{9a302d69def14475b54f9007077536e3,
title = "Radar and photometric observations and shape modeling of contact binary near-Earth Asteroid (8567) 1996 HW1",
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 × 1.6 × 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 5° of ecliptic longitude and latitude (281°, -31°). 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.",
keywords = "Asteroids, Photometry, Radar observations",
author = "Christopher Magri and Howell, {Ellen S.} and Nolan, {Michael C.} and Taylor, {Patrick A.} and Fern{\'a}ndez, {Yanga R.} and Michael Mueller and Vervack, {Ronald J.} and Benner, {Lance A.M.} and Giorgini, {Jon D.} and Ostro, {Steven J.} and Scheeres, {Daniel J.} and Hicks, {Michael D.} and Heath Rhoades and Somers, {James M.} and Gaftonyuk, {Ninel M.} and Kouprianov, {Vladimir V.} and Krugly, {Yurij N.} and Molotov, {Igor E.} and Busch, {Michael W.} and Margot, {Jean Luc} and Vladimir Benishek and Vojislava Protitch-Benishek and Adrian Gal{\'a}d and David Higgins and Peter Ku{\v s}nir{\'a}k and Pray, {Donald P.}",
note = "Funding Information: We thank the two anonymous reviewers for useful reviews, and the Arecibo technical staff for its help with the radar observations. C. Magri, Y.R. Fern{\'a}ndez, and R.J. Vervack Jr. were partially supported by NSF Grant AST-0808064. This material is based upon work supported by the National Aeronautics and Space Administration under Grants NNX10AP87G and NNX10AP64G issued through the Near-Earth Object Observation Program. A. Gal{\'a}d was supported by the Slovak Grant Agency for Science VEGA, Grant 2/0016/09, and the Grant Agency of the Czech Republic, Grant 205/09/1107. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, which is operated by Cornell University under a cooperative agreement with the National Science Foundation. Part of this research was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA). This material is based in part upon work supported by NASA under the Science Mission Directorate Research and Analysis Programs. ",
year = "2011",
month = jul,
doi = "10.1016/j.icarus.2011.02.019",
language = "English (US)",
volume = "214",
pages = "210--227",
journal = "Icarus",
issn = "0019-1035",
publisher = "Academic Press Inc.",
number = "1",
}