Perihelion advance and Yarkovsky drift of near-Earth asteroids: asteroid physical properties, solar oblateness, and general relativity
Perihelion advance and Yarkovsky drift of near-Earth asteroids:
asteroid physical properties, solar oblateness, and general
relativity
Funding
This 5-year investigation is supported by the
Division of Astronomical Sciences of the National Science Foundation.
Abstract
Drs. Jean-Luc Margot and Jon Giorgini will obtain and interpret
high-precision radar range measurements of twelve near-Earth asteroids
(NEAs) that have trajectories strongly affected by the light of the
Sun, the shape of the Sun, and general relativistic effects. Asteroid
orbits are influenced by the absorption and reemission of solar
energy, the so-called Yarkovsky effect. These changes to the motion
will be quantified with the radar measurements in order to constrain
the densities, compositions, and thermal properties of NEAs. Other
perturbations to NEA orbits arise as a result of the non-uniformity of
the gravitational field of the oblate Sun. The ranging data to the
twelve NEAs will provide a direct probe of the mass distribution in
the Suns interior by measuring changes to the asteroid
trajectories. Radar tests of general relativity (GR) will also be
improved by quantifying the perihelion advance of NEAs that reach deep
inside the gravitational well of the Sun. The GR effects can be
separated from the effects of oblateness as they have a different
dependence on the size, eccentricity, and inclination of the NEA
orbits. Both GR and oblateness effects can be separated from the
distinct signature of the Yarkovsky drift. Most of the measurements
will be performed with the planetary radar on the Arecibo
telescope. Analysis of the results will make use of orbital
determination software at JPL. High precision measurements in this
extreme dynamical regime will provide unique observational constraints
and will test current models of asteroid physics, solar physics, and
fundamental physics.
Objects observed so far
Top priority targets
Our list of top priority targets is maintained in a wiki,
which also lists orbital parameters, years of apparitions, and years
of detections.
References
J.L. Margot,
Candidate Asteroids for Discerning General Relativity and Solar
Oblateness, American Astronomical Society, DDA meeting #34, #06.13,
2003.
J.L. Margot
and J.D. Giorgini, Probing general relativity with radar astrometry in the
inner solar system, Proceedings of IAU symposium 261: Relativity in
Fundamental Astronomy - Dynamics, Reference Frames and Data Analysis,
261, p. 183-188, 2010.
Contact information
Jean-Luc Margot
Associate Professor
Dept. of Earth and Space Sciences
Dept. of Physics and Astronomy
University of California, Los Angeles
595 Charles Young Drive East
Los Angeles, CA 90095
(310) 206 8345
http://www2.ess.ucla.edu/~jlm
jlm@ess.ucla.edu
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