JVI Himalia: New Compositional Evidence and Interpretations for the Origin of Jupiter's Small Satellites

Abstract

New narrowband spectrophotometric data of JVI Himalia support its C-type classification. Two spectra taken on successive nights are rotationally sampled. The new spectra confirm the presence of a weak absorption feature centered near 0.7 μm attributed to oxidized iron in phyllosilicates, products of aqueous alteration. Evaluation of the UBV photometry of JVI Himalia and JVII Elara compared to the UBV photometry of C-class (and subclass) asteroids showing spectral evidence of the 0.7-μm absorption feature, and the new spectra compared with ECAS photometry of B-, F-, and some C-class asteroids, suggests that JVI Himalia is an F-class asteroid, a subclass of the Cs. We propose that the parent body of the prograde outer jovian satellites originated as part of the dynamical Nysa asteroid family. Evolutionary models of the Jovian system are used to address the capture and dispersal of the irregular satellites.