1. Study of the plutino object (208996) 2003 AZ84 from stellar occultations: size, shape and topographic features
- Author
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Dias-Oliveira, A., Sicardy, B., Ortiz, J. L., Braga-Ribas, F., Leiva, R., Vieira-Martins, R., Benedetti-Rossi, G., Camargo, J. I. B., Assafin, M., Gomes-Junior, A. R., Baug, T., Chandrasekhar, T., Desmars, J., Duffard, R., Santos-Sanz, P., Ergang, Z., Ganesh, S., Ikari, Y., Irawati, P., Jain, J., Liying, Z., Richichi, A., Shengbang, Q., Behrend, R., Benkhaldoun, Z., Brosch, N., Daassou, A., Frappa, E., Gal-Yam, A., Garcia-Lozano, R., Gillon, M., Jehin, E., Kaspi, S., Klotz, A., Lecacheux, J., Mahasena, P., Manfroid, J., Manulis, I., Maury, A., Mohan, V., Morales, N., Ofek, E., Rinner, C., Sharma, A., Sposetti, S., Tanga, P., Thirouin, A., Vachier, F., Widemann, T., Asai, A., Watanabe, Hayato, Watanabe, Hiroyuki, Owada, M., Yamamura, H., Hayamizu, T., Bradshaw, J., Kerr, S., Tomioka, H., Andersson, S., Dangl, G., Haymes, T., Naves, R., and Wortmann, G
- Subjects
Astrophysics - Earth and Planetary Astrophysics - Abstract
We present results derived from four stellar occultations by the plutino object (208996) 2003~AZ$_{84}$, detected at January 8, 2011 (single-chord event), February 3, 2012 (multi-chord), December 2, 2013 (single-chord) and November 15, 2014 (multi-chord). Our observations rule out an oblate spheroid solution for 2003~AZ$_{84}$'s shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semi axes $(470 \pm 20) \times (383 \pm 10) \times (245 \pm 8)$~km % axis ratios $b/a= 0.82 \pm 0.05$ and $c/a= 0.52 \pm 0.02$, can better account for all our occultation observations. Combining these dimensions with the rotation period of the body (6.75~h) and the amplitude of its rotation light curve, we derive a density $\rho=0.87 \pm 0.01$~g~cm$^{-3}$ a geometric albedo $p_V= 0.097 \pm 0.009$. A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003~AZ$_{84}$'s limb, that can be interpreted as an abrupt chasm of width $\sim 23$~km and depth $> 8$~km or a smooth depression of width $\sim 80$~km and depth $\sim 13$~km (or an intermediate feature between those two extremes).
- Published
- 2017
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