Dinâmica de partículas micrométricas no arco do anel G de Saturno

• Autor(a) principal: Madeira, Gustavo Oliveira [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155299; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-03-30/000881501.pdf
• topic: Planetas; Satelites; Radiação solar; Dinamica da particula; Solar radiation

Images obtained by the spacecraft Cassini in 2004 reveal the existence of a dense arc of material in the G ring, confined in 167500 km from Saturn's center, due an eccentric corotation resonance 7:6 with the satellite Mimas. In 2008, the same spacecraft detected a satellite immersed in the arc, Aegaeon, which is believed to be the main source of material. In this work we analyze the dynamics of micrometric particles in the arc of the G ring. According to observational data, this size of particles is the most significant in the arc. First, the dynamics of micrometric particles was analyzed including the effects of planetary oblateness (J2, J4 and J6), Mimas, Aegaeon and Thetys. We find that the resonance with Mimas is capable to confine the particles into the arc's region, although part of them collides with Aegaeon. We also included the effects of solar radiation pressure by considering particles of 1µm, 3µm, 5µm, 10µm, 30µm, 50µm and 100µm in radius. As result we have this perturbation causes periodic variations in the eccentricity of the particles, leading the grain's orbit crosses many times the Aegaeon's orbit. Thus, Aegaeon is responsible for clearing almost all the arc, particles smaller than 10µm live less than 50 years. Considering these particles, the arc is almost void of particles smaller than 10µm in less than 100 years. Therefore, the current concentration of micrometric particles in the arc can only be explained, through the mass ejection mechanism by Aegaeon and other larger bodies, there must be another material reset mechanism in the region. If not, the current arc of the G ring should be a new structure that will deteriorate in the coming decades, which is not an exclusive phenomenon of the arc of G ring. According to observations, the same phenomenon is happening in the arcs of Neptune's Adams ring