Comparison of our model results for the limb polarization with literature values. Top panel: geometric albedo A_g from the literature (dashed, see also Fig. 1) and from our model (solid). Bottom panel: integrated limb polarization p(0°) of our model for the complete wavelength range (solid), and the HST filter pass bands (+), as well as our HST polarimetry observations (×) given in Table 3.