The trans-Neptunian object (84922) 2003 VS2 through stellar occultations

• Autor(a) principal: Benedetti-Rossi, Gustavo
• Data de Publicação: 2019
• Outros Autores: Santos-Sanz, P., Ortiz, J. L., Assafin, M., Sicardy, B., Morales, N., Vieira-Martins, R., Duffard, R., Braga-Ribas, F., Rommel, F. L., Camargo, J. I.B., Desmars, J., Colas, A. F., Vachier, F., Alvarez-Candal, A., Fernández-Valenzuela, E., Almenares, L., Artola, R., Baum, T. P., Behrend, R., Bérard, D., Bianco, F. B., Brosch, N., Ceretta, A., Colazo, C. A., Gomes, A. R. [UNESP], Ivanov, V. D., Jehin, E., Kaspi, S., Lecacheux, J., Maury, A., Melia, R., Moindrot, S., Morgado, B., Opitom, C., Peyrot, A., Pollock, J., Pratt, A., Roland, S., Spagnotto, J., Tancredi, G., Teng, J. P., Cacella, P., Emilio, M., Feys, F., Gil-Hutton, R., Jacques, C., Machado, D. I., Malacarne, M., Manulis, I., Milone, A. C., Rojas, G., Sfair, R. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.3847/1538-3881/ab3b05; http://hdl.handle.net/11449/198579
• topic: Kuiper belt (893); Trans-Neptunian objects (1705); Unified Astronomy Thesaurus concepts)

We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by the plutino object (84922) 2003 VS2. From the single-chord occultations in 2013 and 2014 we obtained accurate astrometric positions for the object, while from the multi-chord occultation on 2014 November 7, we obtained the parameters of the best-fitting ellipse to the limb of the body at the time of occultation. We also obtained short-term photometry data for the body in order to derive its rotational phase during the occultation. The rotational light curve present a peak-to-peak amplitude of 0.141 ± 0.009 mag. This allows us to reconstruct the 3D shape of the body, with principal semi-axes of a = 313.8 ± 7.1 km, b = 265.5- + 9.8 8.8 km, and c = 247.3- + 43.6 26.6 km, which is not consistent with a Jacobi triaxial equilibrium figure. The derived spherical volume equivalent diameter of 548.3- + 44.6 29.5 km is about 5% larger than the radiometric diameter of 2003 VS2 derived from Herschel data of 523 ± 35 km, but still compatible with it within error bars. From those results we can also derive the geometric albedo (0.123- + 0.014 0.015) and, under the assumption that the object is a Maclaurin spheroid, the density r = 1400- + 300 1000 for the plutino. The disappearances and reappearances of the star during the occultations do not show any compelling evidence for a global atmosphere considering a pressure upper limit of about 1 microbar for a pure nitrogen atmosphere, nor secondary features (e.g., rings or satellite) around the main body.