The authors developed a general numerical algorithm for obtaining simulated lightcurves of "spotted" asteroids and varied the most critical geometrical and physical parameters (albedo contrast, size, and position of the spots; polar coordinates, and shape of the asteroid). They then analyzed the case of 4 Vesta by assuming an axisymmetric ellipsoidal shape with a large brighter region on one hemisphere, in agreement with the results of photometric and polarimetric observations. Fitting the numerical simulations to the available data, the authors obtained the flattening of the ellipsoid (0.79±0.03), the albedo contrast and geometry of the brighter region, and the orientation of the polar axis. If the derived flattening corresponds to the equilibrium shape of a nearly homogeneous body, a density of 2.4±0.3 g cm-3 can be inferred.
Flattening, pole, and albedo features of 4 Vesta from photometric data
PAOLICCHI, PAOLO
1987
Abstract
The authors developed a general numerical algorithm for obtaining simulated lightcurves of "spotted" asteroids and varied the most critical geometrical and physical parameters (albedo contrast, size, and position of the spots; polar coordinates, and shape of the asteroid). They then analyzed the case of 4 Vesta by assuming an axisymmetric ellipsoidal shape with a large brighter region on one hemisphere, in agreement with the results of photometric and polarimetric observations. Fitting the numerical simulations to the available data, the authors obtained the flattening of the ellipsoid (0.79±0.03), the albedo contrast and geometry of the brighter region, and the orientation of the polar axis. If the derived flattening corresponds to the equilibrium shape of a nearly homogeneous body, a density of 2.4±0.3 g cm-3 can be inferred.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
