日本地球惑星科学連合2018年大会

講演情報

[EE] Eveningポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS03] 太陽系小天体研究:現状の理解と将来の展望

2018年5月23日(水) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:石黒 正晃(ソウル大学物理天文学科)、中本 泰史(東京工業大学)、荒川 政彦(神戸大学大学院理学研究科、共同)、安部 正真(宇宙航空研究開発機構宇宙科学研究所)

[PPS03-P22] Update of Imaging Polarimetry Survey on Cometary Dust Coma Activities

*古荘 玲子1渡部 潤一2 (1.都留文科大学、2.国立天文台天文情報センター)

キーワード:彗星、偏光撮像、塵

Polarimetry is a powerful tool to study physical properties of cometary dust grains. It is well known that sunlight scattered by dust grains in cometary coma is partially linearly polarized. The polarization degree is a function of complex refractive indices, size distribution, shape, and scattering phase angle of dust grains. Imaging polarimetry of comets gives us a valuable clue to study dust grain activities in cometary coma. It had been recognized that feature of higher linear polarization degree relevant to a dust jet in linear polarization maps of some comets. The feature might indicate the difference of local distribution of size and/or material of dust grains in a coma by the jet activity and so on.

To study such dust grain activities in cometary coma, we have started the optical imaging polarimetry survey on cometary dust coma activities, by using our instrument called "Polarimetric Imager for COmets (PICO)" [1]. In the early phase of this survey, 0.65-m reflector at Gunma Astronomical Observatory and 1-m telescope at Lulin Observatory, Taiwan, were used for observations. Since 2006, our survey has been performed by using the 0.5-m reflector at Mitaka, National Astronomical Observatory of Japan. Up to now, we observed 26 comets/nuclei in total, including 7 short periodic comets and one pair of split cometary nuclei of 73P/Schwassmann-Wachmann. We present the latest results of our polarimetry survey.

[1] Ikeda Y. et al. (2007), PASJ, 59, 1017