Characterization of Near-Earth Asteroid 2009 KC3 from Radar and Thermal Infrared Observations

Taylor, P. A., Howell, E. S., Nolan, M. C., Benner, L. A. M., Brozovic, M., Giorgini, J. D., Vervack, R. J., Fernandez, Y. R., Magri, C. & Mueller, M., 1-Oct-2010, In : Bulletin of the American Astronomical Society. 42, p. 1080

Research output: Contribution to journalMeeting AbstractAcademic

  • Patrick A. Taylor
  • E. S. Howell
  • M. C. Nolan
  • L. A. M. Benner
  • M. Brozovic
  • J. D. Giorgini
  • R. J. Vervack
  • Y. R. Fernandez
  • C. Magri
  • M. Mueller
We will report on the size, shape, spin state, and reflective and thermal properties of C-type, Apollo-class, potentially hazardous, near-Earth asteroid 2009 KC3 (a = 3.2 AU, e = 0.7, i = 10 deg). This object was discovered by the Siding Spring Survey in May 2009 and subsequently observed in the late summer using the Goldstone (8560 MHz, 3.5 cm) and Arecibo (2380 MHz, 12.6 cm) radar systems from August 22-29 as well as with the SpeX instrument on the NASA IRTF on August 30 and September 21. Radar images reveal a roughly spheroidal body about 1.2 km in diameter that is slightly asymmetric and elongated. Tracking of surface features and the echo bandwidth suggest a period near 12 hours, which is in agreement with a period of 11.768 hours found from lightcurve observations (P. Pravec, pers. comm.). A consistent decrease in echo bandwidth during the radar observations implies the line of sight was moving away from the equator. Radar images with resolution as fine as 7.5 m per pixel show an indentation on the leading edge (possibly a crater) and radar-bright features beyond the leading edge. The S-band circular polarization ratio of 0.25 is near the median observed among near-Earth asteroids. Thermal emission between 2 and 4 microns is essentially unchanged in SpeX observations three weeks apart despite a change in phase angle from 98 deg to 49 degrees and an increase in heliocentric distance by 0.1 AU. Furthermore, the thermal parameters derived for 2009 KC3 during a single observation do not accurately predict the thermal emission at a later time in a different viewing geometry. Determination of the shape and spin pole will help us understand how much rotation phase and illumination effects affected the thermal observations.
Original languageEnglish
Pages (from-to)1080
JournalBulletin of the American Astronomical Society
Publication statusPublished - 1-Oct-2010
Event42nd Meeting, American Astronomical Society, 2010 - Pasadena, United States
Duration: 4-Oct-20108-Oct-2010


42nd Meeting, American Astronomical Society, 2010


Pasadena, United States

Event: Conference

ID: 20776665