[PPS03-P03] Polarimetry of Near-Earth Asteroid (3200) Phaethon on 2017 December
Keywords:Asteroid, Phaethon, Polarimetry
In order to study properties of surface materials of Phaethon, imaging polarimetric observations were carried out for 13 consecutive nights from 2017 December 9 through December 21. The linear polarization images of Phaethon were acquired with the Polarimetric Imager for COmet (PICO)  mounted on the Cassegrain focus of the 50 cm Telescope for Public Outreach at Mitaka Campus of National Astronomical Observatory of Japan, Tokyo, Japan . We used the standard Johnson-Cousins RC band filter  for all observations. PICO is double-beam type polarimeter, and the field of view was ~13’ by 6’ on the sky for each image. The heliocentric and geocentric distances of Phaethon were 1.13 – 0.93 au and 0.07 – 0.11 au, respectively. We could take polarimetric data of Phaethon with very wide range of phase angle of 19.1° – 114.3°. We present the polarization curve and discuss properties of surface materials of Phaethon.
This research was supported by a Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Fellows, 15J10864 (YS) and supported by JSPS KAKENHI Grant Number 17H06459 (NN).
 Jewitt D. et al. (2013), ApJL, 771, L36.
 Li J. & Jewitt D. (2013), AJ, 145, 154.
 Williams I. P. & Wu Z. (1993), MNRAS, 262, 231.
 Ikeda Y. et al. (2007), PASJ, 59, 1017
 Bessell M. S. (2005), ARA&A, 43, 293