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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:43 |
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Conference: Bucharest University Faculty of Physics 2018 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
The case of 2012 TC4
Authors:
Adrian ȘONKA(1,3), Mirel BÎRLAN(2), Andreea Ioana GORNEA(3,4), Simon ANGHEL(3)
*
Affiliation:
1) Faculty of Physics, University of Bucharest
2) IMCCE, Observatoire de Paris 77 av Denfert Rochereau, 75014 Paris cedex, France
3) Astronomical Institute of Romanian Academy Str. Cutitul de Argint 5, 040557 Bucharest, Romania
4) Technical University of Civil Engineering Bucharest Lacul Tei Bvd. 122 - 124, 020396 Bucharest, Romania
E-mail
sonka.adrian@gmail.com
Keywords:
planetology, Near Earth Asteroid, minor planets, photometry
Abstract:
The asteroid 2012 TC4 was discovered on 4th Oct 2012, by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) at Haleakala Observatory on the Hawaiian Island of Maui, in the United States. In 2017, 2012 TC4 had a close approach with the Earth on October 12th, being at only 50,151 km from our planet. It became bright enough to be observable with small telescopes during its fast movement across the sky. Although it was not observable from our longitude at minimum distance (2017-Oct-12 05:42 UT), we observed the asteroid on two prior nights. According to JPL Solar System Dynamics, this was the closest approach of 2012 TC4 since the discovery (2012-Oct-12 05:30 UT) and until 2108 (the furthest time for which a good ephemeris can be computed). The observations were carried at the Astronomical Institute of the Romanian Academy (IAU MPC code 073). We used the 0.38 meter f/6 Ritchey-Chretien telescope and a SBIG STL-11000M CCD camera, cooled down to −20 ◦C. The field-of-view is 44x29 arcmin and the pixel scale of 1.3 arcsec/pixel (a 2x2 binning was used during the run, in order to minimize image download time from sensor). The observations were carried in two nights, with a total observing time of 6.4 hours, while the distance from the Earth decreased by a factor of three. The apparent magnitude decreased and the asteroid sky motion attained a value of 117”/min. We present three hours of photometry for minor planet 2012 TC4, during the close approach . Our observations and data analysis show a fast spinning asteroid with a period of 0.204 ± 0.001 hours, a non-principal axis rotator with a ratio of about 1.7 between axis in the assumption of an ellipsoidal shape. This synodical period is compatible with a monolithic structure of the object.
Acknowledgement:
This work was supported by a grant of the Ministry of National Education and Scientific Research, RDI Program for Space Technology and Advanced Research - STAR, project number 513.
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