Photometric geodesy of mainbelt asteroids II. Analysis of lightcurves for poles, periods, and shapes
Abstract
Twentyfive of the twentysix asteroids included in the "photometric geodesy" program (S.J. Weidenschilling, C.R. Chapman, D.R. Davis, R. Greenberg, D.H. Levy, and S. Vail, Icarus 70, 191245, 1987) have been studied on the assumption that asteroids can be modeled as smooth, featureless, triaxial ellipsoids rotating about their shortest axes. Using all lightcurves available, rotational poles have been obtained by three independent methods. With these poles each asteroid's sidereal period and triaxial ellipsoid axial ratios have been determined, along with the associated photometric parameters. The studied asteroids seem to have rotational poles that do not lie near their orbital planes. Two distinct types of asteroids may be indicated by a stronger solar phase angleamplitude dependence (perhaps due to a rougher surface?) and a weaker phaseamplitude (smoother?) relation. Although no strict hydrostatic equilibrium shape is found, several asteroids are close enough to equilibrium figures to allow an estimate of their densities to be made under certain assumptions.
 Publication:

Icarus
 Pub Date:
 October 1988
 DOI:
 10.1016/00191035(88)90139X
 Bibcode:
 1988Icar...76...19D
 Keywords:

 Asteroids;
 Astronomical Photometry;
 Axes Of Rotation;
 Celestial Geodesy;
 Astrometry;
 Astronomical Models;
 Celestial Mechanics;
 Cosmology;
 Ellipsoids;
 Light Curve;
 Lunar and Planetary Exploration