Physical properties of near-earth asteroid 2011 MD

M. Mommert, D. Farnocchia, J. L. Hora, S. R. Chesley, David E Trilling, P. W. Chodas, M. Mueller, A. W. Harris, H. A. Smith, G. G. Fazio

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

We report on observations of near-Earth asteroid 2011 MD with the Spitzer Space Telescope. We have spent 19.9 hr of observing time with channel 2 (4.5 μm) of the Infrared Array Camera and detected the target within the 2σ positional uncertainty ellipse. Using an asteroid thermophysical model and a model of nongravitational forces acting upon the object, we constrain the physical properties of 2011 MD, based on the measured flux density and available astrometry data. We estimate 2011 MD to be (6) m in diameter with a geometric albedo of 0.3 (uncertainties are 1σ). We find the asteroid's most probable bulk density to be (1.1) g cm-3, which implies a total mass of (50-350) t and a macroporosity of ≥65%, assuming a material bulk density typical of non-primitive meteorite materials. A high degree of macroporosity suggests that 2011 MD is a rubble-pile asteroid, the rotation of which is more likely to be retrograde than prograde.

Original languageEnglish (US)
Article numberL22
JournalAstrophysical Journal Letters
Volume789
Issue number1
DOIs
StatePublished - Jul 1 2014

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asteroids
asteroid
physical property
physical properties
bulk density
Space Infrared Telescope Facility
astrometry
ellipse
ellipses
meteorites
piles
albedo
meteorite
pile
flux density
cameras
estimates
material

Keywords

  • infrared: planetary systems
  • minor planets asteroids: individual (2011 MD)

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Mommert, M., Farnocchia, D., Hora, J. L., Chesley, S. R., Trilling, D. E., Chodas, P. W., ... Fazio, G. G. (2014). Physical properties of near-earth asteroid 2011 MD. Astrophysical Journal Letters, 789(1), [L22]. https://doi.org/10.1088/2041-8205/789/1/L22

Physical properties of near-earth asteroid 2011 MD. / Mommert, M.; Farnocchia, D.; Hora, J. L.; Chesley, S. R.; Trilling, David E; Chodas, P. W.; Mueller, M.; Harris, A. W.; Smith, H. A.; Fazio, G. G.

In: Astrophysical Journal Letters, Vol. 789, No. 1, L22, 01.07.2014.

Research output: Contribution to journalArticle

Mommert, M, Farnocchia, D, Hora, JL, Chesley, SR, Trilling, DE, Chodas, PW, Mueller, M, Harris, AW, Smith, HA & Fazio, GG 2014, 'Physical properties of near-earth asteroid 2011 MD', Astrophysical Journal Letters, vol. 789, no. 1, L22. https://doi.org/10.1088/2041-8205/789/1/L22
Mommert M, Farnocchia D, Hora JL, Chesley SR, Trilling DE, Chodas PW et al. Physical properties of near-earth asteroid 2011 MD. Astrophysical Journal Letters. 2014 Jul 1;789(1). L22. https://doi.org/10.1088/2041-8205/789/1/L22
Mommert, M. ; Farnocchia, D. ; Hora, J. L. ; Chesley, S. R. ; Trilling, David E ; Chodas, P. W. ; Mueller, M. ; Harris, A. W. ; Smith, H. A. ; Fazio, G. G. / Physical properties of near-earth asteroid 2011 MD. In: Astrophysical Journal Letters. 2014 ; Vol. 789, No. 1.
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