Observed DoLP data of the coma (crosses) and tail (circles) of comet C/2023 A3, with empirical DoLP phase curves fit as described in Sect. 3.1. Red crosses indicate valid broadband DoLP measurements of the coma with the polarization camera, black crosses denote EMPOL measurements of Dec 05, 2024, in the SLOAN i and z band and of Mar 06, 2025, in the SLOAN r band, respectively. Dark blue circles indicate valid broadband DoLP measurements of the tail, the cyan circle corresponds to an inaccurate measurement, and the magenta circles denote upper bounds of the tail’s DoLP due to low SNR_F (Sect. 2.2). The blue phase curve was fit to the measurements marked by blue circles only.