In both the
Tholen and
SMASS taxonomy,
Belgica is classified as a common stony
S-type asteroid.
Rotation period Between December 2012, and January 2013, photometric observations of
Belgica were taken at several observatories in Italy, the Czech Republic, Spain and the United States by astronomers Luis Martinez, Lorenzo Franco, Andrea Ferrero, Petr Pravec, and Stefano Padovan. They gave three concurring
lightcurves with a
rotation period of 2.709 hours and a brightness variation of 0.08 to 0.10
magnitude, indicating a nearly spheroidal shape for the asteroid's body ().
Satellite The photometric observations also revealed, that
Belgica is a
binary system with an
asteroid moon, approximately 36% the diameter of its primary,
orbiting it every hours. Johnston's archive derives a diameter of 3.53 kilometers and estimates a
semi-major axis of 34 kilometer for the moon.
Diameter and albedo According to the survey carried out by NASA's
Wide-field Infrared Survey Explorer with its subsequent
NEOWISE mission,
Belgica measures 9.78 and 10.406 kilometers in diameter and its surface has an
albedo of 0.301 and 0.273, respectively, while the
Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and derives a diameter of 10.94 kilometers with an
absolute magnitude of 12.17. This agrees with the estimated diameter of kilometers by Franco et al. == Naming ==