Interpretation of polarimetric observations of hyperbolic comets

Polarimetric observations of comet C/2013 X1 (PANSTARRS) were compared with polarimetric data taken from the Polarimetric Comet Observations Database. To obtain a synthetic phase dependence of the degree of linear polarization of hyperbolic comets, the data were interpreted using computer simulations. In this case, computer simulation means calculating the characteristics of light scattered by particles of irregular shape and a certain chemical composition. Simulations showed that the dust ball would have to be 74 % amorphous carbon, 25 % magnesium-rich silicates, and 1 % water ice to reproduce the observed linear polarization values.