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

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...

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Autores: Benedetti-Rossi, Gustavo; 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: Artículo
Estado:Published version
Fecha de publicación:2019
País:Brasil
Institución:UNESP
Repositorio:Repositório Institucional da UNESP
Lenguaje:Inglés
OAI Identifier:oai:repositorio.unesp.br:11449/198579
Acceso en línea:http://dx.doi.org/10.3847/1538-3881/ab3b05
http://hdl.handle.net/11449/198579
Nivel de acceso:Acceso abierto
Palabra clave:Kuiper belt (893)
Trans-Neptunian objects (1705)
Unified Astronomy Thesaurus concepts)
Sumario: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.

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