Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect

Science

Volumn 316, Issue 5822, 2007, Pages 274-277

  Taylor, Patrick A ^a   Margot, Jean Luc ^a   Vokrouhlický, David ^b   Scheeres, Daniel J ^c   Pravec, Petr ^d   Lowry, Stephen C ^e   Fitzsimmons, Alan ^e   Nolan, Michael C ^f   Ostro, Steven J ^g   Benner, Lance A M ^g   Giorgini, Jon D ^g   Magri, Christopher ^h  

^a Department of Population Medicine and Diagnostic Sciences   (United States)

^b CHARLES UNIVERSITY   (Czech Republic)

^c UNIVERSITY OF MICHIGAN   (United States)

^d ASTRONOMICAL INSTITUTE   (Czech Republic)

^e QUEEN'S UNIVERSITY BELFAST   (United Kingdom)

^f Arecibo Observatory   (United States)

^g CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

^h UNIVERSITY OF MAINE AT FARMINGTON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ASTEROID; DETECTION METHOD; RADAR; ROTATION;

ARTICLE; ASTRONOMY; OBSERVATION; OPTICS; PREDICTION; PRIORITY JOURNAL; SUNLIGHT; TELECOMMUNICATION; THEORETICAL STUDY;

EID: 34247339711     PISSN: 00368075     EISSN: 10959203     Source Type: Journal    
DOI: 10.1126/science.1139038     Document Type: Article

References (29)

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19. Resolution in time delay, and equivalently range, is achieved by transmitting a time-dependent signal and analyzing the received signal according to arrival time. The time increment τ used in the transmitted signal yields a range resolution cτ/2, where c is the speed of light.
20. We typically define the limb-to-limb bandwidth as the full width of the radar echo at the level of twice the root mean square (RMS) of the off-DC, off-target noise. The exception is the strong 2004 Arecibo data, for which we use 10 times the RMS as the threshold to avoid contributions from frequency sidelobes.
21. This assumes PH5 is a principal axis (PA) rotator where the spin axis remains fixed in inertial space and aligned with the axis of maximum moment of inertia. The spin axis of PH5 must then be oriented such that the angles it makes with the lines of sight satisfy the observed bandwidths (17). The damping time scale (28) to PA rotation for PH5 is of order 0.1 million years.
22. Materials and methods are available as supporting material on Science Online.
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29. We thank the staffs of the Arecibo Observatory and the Goldstone Solar System Radar for their support in performing this research. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, which is operated by Cornell University under a cooperative agreement with NSF. Some of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. This material is based in part on work supported by NASA under the Science Mission Directorate Research and Analysis Programs. P.A.T. and J.L.M. were partially supported by NASA grant NNG04GN31G. The work of P.P. and D.V. was supported by the Grant Agency of the Czech Republic. D.J.S. acknowledges support from the NASA Planetary Geology and Geophysics Program. S.C.L. and A.F. acknowledge support from the Leverhulme Trust and PPARC, respectively. C.M. was partially supported by NSF grant AST-0205975. The International Astronomical Union has approved the name YORP for asteroid (54509) 2000 PH5.