Study of the Plutino Object (208996) 2003 AZ<SUB>84</SUB> from Stellar Occultations: Size, Shape, and Topographic Features

DOI: 
10.3847/1538-3881/aa74e9
Publication date: 
01/07/2017
Main author: 
Dias-Oliveira, A.
IAA authors: 
Ortiz, J. L.;Duffard, R.;Santos-Sanz, P.;Morales, N.
Authors: 
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-Júnior, 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.;Hayato, Watanabe;Hiroyuki, Watanabe;Owada, M.;Yamamura, H.;Hayamizu, T.;Bradshaw, J.;Kerr, S.;Tomioka, H.;Andersson, S.;Dangl, G.;Haymes, T.;Naves, R.;Wortmann, G.
Journal: 
The Astronomical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
154
Pages: 
22
Abstract: 

We present results derived from four stellar occultations by the plutino object (208996) 2003 AZ<SUB>84</SUB>, 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 AZ<SUB>84</SUB>'s shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semiaxes (470+/- 20)× (383+/- 10)× (245+/- 8) 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 ρ =0.87+/- 0.01 g cm<SUP>−3</SUP>, a geometric albedo {p}<SUB>V</SUB>=0.097+/- 0.009. A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003 AZ<SUB>84</SUB>'s limb, which can be interpreted as an abrupt chasm of width ∼23 km and depth 〉 8 km, or a smooth depression of width ∼80 km and depth ∼13 km (or an intermediate feature between those two extremes).

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85024406375&doi=10.3847%2f1538-3881%2faa74e9&partnerID=40&md5=7c4b970d98b8d75a2eeab578134543af
ADS Bibcode: 
2017AJ....154...22D
Keywords: 
Kuiper belt objects: individual: 208996;2003AZ84;occultations;planets and satellites: fundamental parameters;planets and satellites: surfaces;Astrophysics - Earth and Planetary Astrophysics