C/2020 S3 (Erasmus): Comet with a presumably transient maximum of linear polarization <i>P</i>max

ABSTRACT We measured the degree of linear polarization Comet C/2020 S3 (Erasmus) on 2020 November 13, 20, 22, and 23, while comet was observed at large phase angles, ? = 62.6°–66.6°. On first two epochs, closely matched what previously in C/1989 X1 (Austin). third epoch, found to rise slightly, latest it rose significantly, exceeding that Austin. last observation, Erasmus appears be more consistent with seen C/1996 B2 (Hyakutake) a similar angle. While such short-term transient behaviour has been previously, Comets Austin Hyakutake belong different classes classifications based amplitude their positive Pmax and, hence, revealed transition from class low-Pmax comets high-Pmax within only few days. Polarization images modelling suggest occurred due decrease relative abundance Mg-rich silicate particles inner coma by 1/3, revealing qualitative change emanations dust nucleus.