Study of the Plutino Object (208996) 2003 AZ84 from Stellar Occultations: Size, Shape, and Topographic Features

A. Dias-Oliveira*, B. Sicardy, J. L. Ortiz, F. Braga-Ribas, R. Leiva, R. Vieira-Martins, G. Benedetti-Rossi, J. I.B. Camargo, M. Assafin, A. R. Gomes-Júnior, T. Baug, T. Chandrasekhar, J. Desmars, R. Duffard, P. Santos-Sanz, Z. Ergang, S. Ganesh, Y. Ikari, P. Irawati, J. JainZ. Liying, A. Richichi, Q. Shengbang, R. Behrend, Z. Benkhaldoun, N. Brosch, A. Daassou, E. Frappa, A. Gal-Yam, R. Garcia-Lozano, M. Gillon, E. Jehin, S. Kaspi, A. Klotz, J. Lecacheux, P. Mahasena, J. Manfroid, I. Manulis, A. Maury, V. Mohan, N. Morales, E. Ofek, C. Rinner, A. Sharma, S. Sposetti, P. Tanga, A. Thirouin, F. Vachier, T. Widemann, A. Asai, Watanabe Hayato, Watanabe Hiroyuki, M. Owada, H. Yamamura, T. Hayamizu, J. Bradshaw, S. Kerr, H. Tomioka, S. Andersson, G. Dangl, T. Haymes, R. Naves, G. Wortmann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We present results derived from four stellar occultations by the plutino object (208996) 2003 AZ84, detected on 2011 January 8 (single-chord event), 2012 February 3 (multi-chord), 2013 December 2 (single-chord), and 2014 November 15 (multi-chord). Our observations rule out an oblate spheroid solution for 2003 AZ84's shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semiaxes km can better account for all our occultation observations. Combining these dimensions with the rotation period of the body (6.75 hr) and the amplitude of its rotation light curve, we derive a density g cm-3, a geometric albedo . A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003 AZ84's limb, which can be interpreted as an abrupt chasm of width ∼23 km and depth km, or a smooth depression of width ∼80 km and depth ∼13 km (or an intermediate feature between those two extremes).

Original languageEnglish
Article number22
JournalAstronomical Journal
Issue number1
StatePublished - Jul 2017


FundersFunder number
Horizon 2020 Framework Programme669416, 687378


    • Kuiper belt objects: individual (208996, 2003AZ84)
    • occultations
    • planets and satellites: fundamental parameters
    • planets and satellites: surfaces


    Dive into the research topics of 'Study of the Plutino Object (208996) 2003 AZ84 from Stellar Occultations: Size, Shape, and Topographic Features'. Together they form a unique fingerprint.

    Cite this