[U-06_28PM2] 太陽系小天体研究の新展開

[U06-19] 内側小惑星帯のベストイドのライトカーブサーベイ

*長谷川 直¹、宮坂 正大²、三戸 洋之³、猿楽 祐樹¹、小澤 友彦⁴、黒田 大介⁵、吉田 道利⁶、柳澤 顕史⁵、清水 康広⁵、長山 省吾⁵、戸田 博之⁵、沖田 喜一⁵、河合 誠之⁷、関口 朋彦⁸、石黒 正晃⁹、安部 正真¹ (1.宇宙航空研究開発機構宇宙科学研究所、2.東京都庁、3.東京大学木曽観測所、4.みさと天文台、5.国立天文台岡山天体物理観測所、6.広島大学宇宙科学センター、7.東京工業大学理工学研究科、8.北海道教育大学教育学部、9.ソウル大学物理天文学科)

キーワード：小惑星, ベスタ

We have made the lightcurve observation of 13 vestoids ((1933) Tinchen, (2011) Veteraniya, (2508) Alupka, (3657) Ermolova, (3900) Knezevic, (4005) Dyagilev, (4383) Suruga, (4434) Nikulin, (4796) Lewis, (6331) 1992 FZ₁, (8645) 1998 TN, (10285) Renemichelsen, and (10320) Reiland). Lightcurves in the R-band of rotation periods were found for (1933) Tinchen, (2011) Veteraniya, (2508) Alupka, (3657) Ermolova, (3900) Knezevic, (4005) Dyagilev, (4383) Suruga, (4796) Lewis, (6331) 1992 FZ₁, (8645) 1998 TN, and (10320) Reiland.The distribution of rotational rates of 59 vestoids in the inner main belt, including 29 members of the Vesta family that are regarded as ejecta from the asteroid (4) Vesta, is inconsistent with the best-fit Maxwellian distribution. This inconsistency may be due to the effect of thermal radiation Yarkovsky- O'Keefe-Radzievskii-Paddack (YORP) torques, and implies that the collision event that formed vestoids is sub-billion to several billion years in age.