OBSERVATIONAL EVIDENCE FOR AN IMPACT ON THE MAIN-BELT ASTEROID (596) SCHEILA

Journal Article · Mon Oct 10 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/740/1/L11· OSTI ID:21565396

Ishiguro, Masateru ^[1]; Hanayama, Hidekazu; Watanabe, Jun-ichi; Miyaji, Takeshi; Fukushima, Hideo ^[2]; Hasegawa, Sunao; Sarugaku, Yuki ^[3]; Fujiwara, Hideaki; Terada, Hiroshi ^[4]; Hsieh, Henry H ^[5]; Vaubaillon, Jeremie J ^[6]; Kawai, Nobuyuki ^[7]; Yanagisawa, Kenshi; Kuroda, Daisuke ^[8]; Ohta, Kouji ^[9]; Hamanowa, Hiromi ^[10]; Kim, Junhan ^[11]; Pyo, Jeonghyun ^[12]

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1. Department of Physics and Astronomy, Seoul National University, Gwanak, Seoul 151-742 (Korea, Republic of)
2. Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, Ishigaki, Okinawa 907-0024 (Japan)
3. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan)
4. Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States)
5. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
6. Observatoire de Paris, I.M.C.C.E., Denfert Rochereau, Bat. A., FR-75014 Paris (France)
7. Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan)
8. Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asaguchi, Okayama 719-0232 (Japan)
9. Department of Astronomy, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
10. Hamanowa Astronomical Observatory, Motomiya, Fukushima 969-1204 (Japan)
11. Yangcheon-gu, Seoul (Korea, Republic of)
12. Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of)

An unexpected outburst was observed around (596) Scheila in 2010 December. We observed (596) Scheila soon after the impact using ground-based telescopes. We succeeded in the detection of a faint linear tail after 2011 February, which provides a clue to determine the dust ejection date. It is found that the dust particles ranging from 0.1-1 {mu}m to 100 {mu}m were ejected into the interplanetary space impulsively on December 3.5 {+-}1.0 day. The ejecta mass was estimated to be (1.5-4.9)x10{sup 8} kg, suggesting that an equivalent mass of a 500-800 m diameter crater was excavated by the event. We also found that the shape of the light curve changed after the impact event probably because fresh material was excavated around the impact site. We conclude that a decameter-sized asteroid collided with (596) Scheila only eight days before the discovery.

• OSTI ID: 21565396
• Journal Information: Astrophysical Journal Letters, Vol. 740, Issue 1; Other Information: DOI: 10.1088/2041-8205/740/1/L11; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTEROIDS
CRATERS
DETECTION
DUSTS
INTERPLANETARY SPACE
CAVITIES
SPACE