日本地球惑星科学連合2019年大会

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[E] 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] Solar System Small Bodies: A New Frontier Arising Hayabusa 2, OSIRIS-REx and Other Projects

2019年5月29日(水) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8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)、安部 正真(宇宙航空研究開発機構宇宙科学研究所)、Olivier S Barnouin(Johns Hopkins University Applied Physics Laboratory)

[PPS03-P17] Polarimetry of (155140) 2005 UD: the Dynamical Association with (3200) Phaethon

*Masateru Ishiguro1Jooyeon Geem1Hiroyuki Naito2Yoonsoo P. Bach1Daisuke Kuroda3Tatsuharu Ono4Seiko Takagi4Mitsuteru Sato4Kiyoshi Kuramoto4Tomohiko Sekiguchi5Masataka Imai6Makoto Watanabe7Katsuhito Ohtsuka8Sunao Hasegawa9Takashi Ito10Fumi Yoshida11Tomoko Arai11 (1.Department of Physics and Astronomy, Seoul National University、2.Nayoro Observatory、3.Okayama Observatory, Kyoto University、4.Department of Cosmosciences, Graduate School of Science, Hokkaido University、5.Hokkaido University of Education、6.National Institute of Advanced Industrial Science and Technology、7.Department of Applied Physics, Okayama University of Science、8.Tokyo Meteor Network、9.Japan Aerospace Exploration Agency、10.National Astronomical Observatory of Japan、11.Planetary Exploration Research Center, Chiba Institute of Technology)

キーワード:Asteroids, Space Mission (Destiny+)

An Apollo-type near--Earth asteroid, (155140) 2005 UD, is considered as a possible fragment from (3200) Phaethon, suggesting that Phaethon precursor body might undergo a catastrophic disruption in the past. Here we present our new observational evidence for supporting these two are common origin. We thus conducted a polarimetric observation in 2018 September-October and found that 2005 UD exhibited a polarimetric property significantly different from those of major taxonomic classes of NEAs (i.e., S- and C-type) but similar to that of Phaethon at a wide range of the solar phase angles. Using the polarimetric data, we derived the geometric albedo of ~0.1. In addition, we made a photometric observation at the opposition (the zero phase angle), and determined the mean absolute magnitude of 17.2, the synodic rotational period 5.23 hr, and the effective diameter 1.5 km in combination with the derived geometric albedo. From these evidence, we found that the Phaethon precursor body might have lost more than a few percents of the mass via a disruption if 2005 UD was indeed ejected from the Phaethon precursor.