... spheres

Figures 2-4, 8 and 9 are only available in electronic form at http://www.edpsciences.org

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... comets

Throughout this paper, the intensity of scattered solar radiation is termed albedo defined by Hanner et al. (1981) as a phase function normalized to the geometric albedo at the backscattered direction, and we use a scattering angle to describe the geometry of a comet and an observer with respect to the Sun, instead of a phase angle, which commonly appears in the literature on cometary observations.

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