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| Author(s): |
Marina Gonzaga de Oliveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Rio Claro. 2018-06-13. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Geociências e Ciências Exatas. Rio Claro |
| Defense date: | 2018-06-06 |
| Advisor: | Tadashi Yokoyama |
| Abstract | |
It is almost a consensus that the planets, when formed, were born with almost zero obliquities. However, for giant planets except Jupiter, the current obliquities ( ) are far from zero. For Saturn, Uranus, and Neptune they are, respectively, 25 . 6 ◦ , 97 . 8 ◦ , 28 . 3 ◦ . In general, the reasons that changed the obliquities are associated to gravitational effects such as collisions or captures in resonances. In this work we intend to build the average system that governs the long period dynamics of the variation of the obliquity of a planet considering the Sun and a satellite with different masses and distances. We will use Andoyer variables, because they are canonical, so averages can be performed rigorously whenever they are made in angle-action variables. The “wooble” issue can be easily incorporated if necessary. We intend with this model to study the variation of the Neptune’s obliquity, but in principle it can also be used in the case of exoplanets (ARMSTRONG et al., 2014). The planet Neptune, apparently is the only one that has no regular primordial satellite, unlike the others. Boué e Laskar (2010), used an additional satellite to explain the Uranus’ obliquity. However, the presence of an additional satellite with very high mass could destabilize the existing primordial ones. In the case of Neptune, the masses of the additional satellites that we intend to use may be much smaller than those used by Boué and Laskar, which eliminates possible destabilization of eventual regular primordial satellites, if they existed. (AU) | |
| FAPESP's process: | 16/07046-4 - Possible Obliquity variations of the planets during planetary migration |
| Grantee: | Marina Gonzaga de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Master |