Title:

Direct Detection of the Yarkovsky Effect via Radar Ranging to Asteroid 
6489 Golevka



Steven R. Chesley 
Jet Propulsion Laboratory


Abstract:

Radar ranging from Arecibo to the half-kilometer near-Earth asteroid
6489 Golevka unambiguously reveals a small nongravitational
acceleration caused by the anisotropic thermal emission of absorbed
sunlight.  The magnitude of this perturbation, known as the Yarkovsky
effect, is a function of the asteroid's mass and surface thermal
characteristics.  Direct detection of the Yarkovsky effect on
asteroids will help to constrain their physical properties, such as
bulk density, and to refine their orbital paths.  Based on the
strength of the detected perturbation, we estimate the bulk density of
Golevka to be 2.7(+0.4/-0.6) g/cm^3.