Asteroid shapes and lightcurve morphology
Abstract
In order to systematically analyze the influence on asteroidal photometric lightcurves of large-scale deviations from triaxial ellipsoidal shapes, a general model is needed for which the variation of a few parameters can describe a wide range of irregular but "realistic" shapes. We adopted a model formed by merging together eight octants of ellipsoids having different semiaxes, with the constraint that adjacent octants must have two equal semiaxes in common. The corresponding lightcurves can then be computed by approximating the surface with a polyhedron formed by a finite number of plane facets. In several cases very irregular lightcurves are obtained, showing intriguing analogies with some puzzling lightcurves of real asteroids. In particular, the variation of lightcurve morphology with aspect angle can lead to changes in the number of extrema and/or an inversion of them, possibly implying an incorrect estimate of the spin axis direction and of the rotation period.
- Publication:
-
Icarus
- Pub Date:
- April 1989
- DOI:
- 10.1016/0019-1035(89)90178-4
- Bibcode:
- 1989Icar...78..298C
- Keywords:
-
- Asteroids;
- Astronomical Models;
- Light Curve;
- Planetology;
- Astronomical Photometry;
- Hypervelocity Impact;
- Morphology;
- Planetary Evolution;
- Shapes;
- ASTEROIDS;
- SHAPE;
- LIGHTCURVES;
- MORPHOLOGY;
- PHOTOMETRY;
- PARAMETERS;
- AXIS;
- MODELS;
- DIAGRAMS;
- CALCULATIONS;
- DEFORMATIONS;
- ALBEDO;
- OPTICAL PROPERTIES;
- ANALYSIS;
- PHYSICAL PROPERTIES