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The population of large asteroids is thought to be primordial and they arethe most direct witnesses of the early history of our Solar System. Thosesatellites allow study of the mass, and hence density and internal structure.We study here the properties of the triple asteroid (107) Camilla fromlightcurves, stellar occultations, optical spectroscopy, and high-contrast andhigh-angular-resolution images and spectro-images. Using 80 positions over 15years, we determine the orbit of its larger satellite to be circular,equatorial, and prograde, with RMS residuals of 7.8 mas. From 11 positions inthree epochs only, in 2015 and 2016, we determine a preliminary orbit for thesecond satellite. We find the orbit to be somewhat eccentric and slightlyinclined to the primary's equatorial plane, reminiscent of the inner satellitesof other asteroid triple systems. Comparison of the near-infrared spectrum ofthe larger satellite reveals no significant difference with Camilla. Hence,these properties argue for a formation of the satellites by excavation fromimpact and re-accumulation of ejecta. We determine the spin and 3-D shape ofCamilla. The model fits well each data set. We determine Camilla to be largerthan reported from modeling of mid-infrared photometry, with aspherical-volume-equivalent diameter of 254 $\pm$ 36 km (3 $\sigma$uncertainty), in agreement with recent results from shape modeling(Hanus2017+). Combining the mass of (1.12 $\pm$ 0.01) $\times$ 10$^{19}$ kgdetermined from the dynamics of the satellites and the volume from the 3-Dshape model, we determine a density of 1,280 $\pm$ 130 SI. From this density,and considering Camilla's spectral similarities with (24) Themis and (65)Cybele (for which water ice coating on surface grains was reported), we infer asilicate-to-ice mass ratio of 1-6, with a 10-30% macroporosity.

Physical, spectral, and dynamical properties of asteroid (107) Camilla and its satellites