Produção Nacional
Revisado por pares
The multichord stellar occultation on 2019 October 22 by the trans-Neptunian object (84922) 2003 VS 2
2022; EDP Sciences; Volume: 663; Linguagem: Inglês
10.1051/0004-6361/202141842
ISSN1432-0746
AutoresMónica Vara-Lubiano, G. Benedetti-Rossi, P. Santos-Sanz, J. L. Ortiz, B. Sicardy, Marcel Popescu, N. Morales, F. L. Rommel, B. E. Morgado, C. L. Pereira, A. Álvarez-Candal, E. Fernández-Valenzuela, D. Souami, D. Ilić, O. Vince, R. Bachev, E. Semkov, Dan Alin Nedelcu, A. Şonka, L. Hudin, Margareta Boacă, V. Inceu, L. Curelaru, R. Gherase, Vlad Turcu, Dan Moldovan, Liviu Mircea, M. Predatu, Mircea Teodorescu, L. Stoian, A. Juravle, F. Braga-Ribas, J. Desmars, R. Duffárd, J. Lecacheux, J. I. B. Camargo, M. Assafin, R. Vieira-Martins, T. Pribulla, Marek Husárik, Peter Sivanič, András Pál, R. Szakáts, Csaba Kiss, J. Alonso-Santiago, A. Frasca, Gyula M. Szabó, A. Derekas, László Szigeti, M. Dróżdż, W. Ogłoza, J. Skvarč, F. Ciabattari, P. Delinčák, P. Di Marcantonio, G. Iafrate, Igor Coretti, Veronica Baldini, P. Baruffetti, O. Klös, V. Dumitrescu, H. Mikuž, Andrej Mohar,
Tópico(s)Geomagnetism and Paleomagnetism Studies
ResumoWe predicted, observed, and analyzed the multichord stellar occultation of the Second Gaia Data Release (Gaia DR2) source 3449076721168026624 (m$_v$ = 14.1 mag) by the plutino object 2003 VS$_2$ (hereafter, VS$_2$) on 2019 October 22. We also carried out photometric observations to derive the rotational light curve amplitude and rotational phase of VS$_2$ during the stellar occultation. Combining the results and assuming a triaxial shape, we derived the 3D shape of VS$_2$. Out of the 39 observatories involved in the observational campaign, 12 sites reported a positive detection; this makes it one of the best observed stellar occultations by a TNO so far. We obtained a rotational light curve amplitude of $Δ$m = 0.264 $\pm$ 0.017 mag, a mean area-equivalent diameter of D$_{A_{eq}}$ = 545 $\pm$ 13 km, and a geometric albedo of 0.134 $\pm$ 0.010. The best triaxial shape obtained for VS$_2$ has semiaxes a = 339 $\pm$ 5 km, b = 235 $\pm$ 6 km, and c = 226 $\pm$ 8 km. The derived aspect angle is $θ$ = 59$° \pm$ 2$°$ or its supplementary $θ$ = 121$° \pm$ 2$°$, depending on the north-pole position. The spherical-volume equivalent diameter is D$_{V_{eq}}$ = 524 $\pm$ 7 km. If we consider large albedo patches on its surface, the semi-major axis of the ellipsoid could be ~10 km smaller. These results are compatible with the previous ones determined from the single-chord 2013 and four-chord 2014 stellar occultations and with the effective diameter and albedo derived from Herschel and Spitzer data. They provide evidence that VS$_2$'s 3D shape is not compatible with a homogeneous triaxial body in hydrostatic equilibrium, but it might be a differentiated body and/or might be sustaining some stress. No secondary features related to rings or material orbiting around VS$_2$ were detected.
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