Shape and Rotational Motion Models for Tumbling and Monolithic Asteroid 2012 TC{sub 4}: High Time Resolution Light Curve with the Tomo-e Gozen Camera
- Japan Spaceguard Association, Bisei Spaceguard Center 1716-3 Okura, Bisei, Ibara, Okayama 714-1411 (Japan)
- Institute of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)
- Department of Earth Science, Okayama University, 1-1-1 Kita-ku Tsushimanaka, Okayama 700-8530 (Japan)
- Center for Astronomy, University of Hyogo 407-2 Nishigaichi, Sayo, Hyogo 679-5313 (Japan)
- Anan Science Center, 8-1 Nagakawa Kamifukui Minami-Kawabuchi, Anan, Tokushima 779-1243 (Japan)
- Nayoro Observatory, 157-1 Nisshin, Nayoro, Hokkaido 096-0066 (Japan)
- Asahikawa Campus, Hokkaido University of Education, 9 Hokumon, Asahikawa, Hokkaido 070-8621 (Japan)
- Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwank-gu, Seoul 08826 (Korea, Republic of)
- Faculty of Engineering, Kindai University, Hiroshima Campus, 1 Takaya Umenobe, Higashi-Hiroshima, Hiroshima 739-2116 (Japan)
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa, 252-5210 (Japan)
We present visible and near-infrared observations of a near-Earth object (NEO), 2012 TC{sub 4}. The NEO 2012 TC{sub 4} approached close to Earth at a distance of about 50,000 km in 2017 October. This close approach provided a practical exercise for planetary defense. This apparition was also an appropriate opportunity to investigate 2012 TC{sub 4}, which is a monolithic asteroid. We conducted the observation campaign of 2012 TC{sub 4} using six small- and medium-sized telescopes. The multiband photometry analysis showed the taxonomic class of 2012 TC{sub 4} to be an X type. In particular, we successfully obtained the high time resolution light curve of 2012 TC{sub 4} with the Tomo-e Gozen camera, which is the world’s first wide-field CMOS camera, mounted on the 1.05 m Schmidt telescope at Kiso Observatory. The shape and rotational motion models of 2012 TC{sub 4} were derived from the light curve. When 2012 TC{sub 4} was assumed to be a triaxial ellipsoid, the rotational and precession periods were 8.47 ± 0.01 minutes and 12.25 ± 0.01 minutes, respectively, with the long-axis mode. This indicates that 2012 TC{sub 4} is a tumbling and monolithic asteroid. The shape models showed the plausible axial lengths to be 6.2 × 8.0 × 14.9 m or 3.3 × 8.0 × 14.3 m. The flattened and elongated shape indicates that 2012 TC{sub 4} is a fragment produced by an impact event. We also estimated the excitation timescale, which implied that the impact event happened within ∼3 × 10{sup 5} yr and 2012 TC{sub 4} has a fresh surface.
- OSTI ID:
- 22897343
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 157, Issue 4; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spin Change of Asteroid 2012 TC4 Probably by Radiation Torques
The discovery of cometary activity in near-Earth asteroid (3552) Don Quixote