Tadashi Yokoyama

• Abstract

  Close Encounters in orbital dynamics occur when, under the gravitational force, one body has a trajectory that takes it to a position close to another body. The orbital evolution of these two bodies will depend on the dynamical and geometrical parameters of the encounter. The outcome can be, for example: i) a collision between the two bodies; ii) a drastic change in the trajectory of one …

  Close approach problems in orbital dynamics, AP.TEM
• The saturnian satellites and possible effects of the planetary migration, AR.EXT
• Inner satellites of neptune: i-the mutual disturbing function., AR.EXT

(Only some records are available in English at this moment)

• Abstract

  The current surface of Ariel, clearly reveals that it might have suffered important effects of tides, caused by passage through orbital resonances. If Miranda and Umbriel necessarily crossed 3:1 resonance (as it is believed), then certainly Ariel and Umbriel crossed 5:3 resonance. In this work, this resonance will be considered, taking the spatial case including all regular satellites of …

  Ariel and Umbriel in the 5:3 resonance, BP.IC

• Abstract

  It is almost a consensus that the giant planets were formed with almost zero obliquity. However except Jupiter, the present obliquity of Saturn, Uranus and Neptune, are far from zero. They are : 25.6 ,97.8, 28.3, respectively. Usually, the reason of these high values are linked to gravitational effects like collisions or capture into resonances. In this work we intend to build an averag…

  Possible Obliquity variations of the planets during planetary migration, BP.MS

• Abstract

  It is believed that Pluto-Charon is in a double (1:1) synchrounism. It is a very particular system: Pluto eccentricity (0.2) is similar to Mercury’s one, however they have different obliquities: Pluto s obliquity varies in the range 103 to 128 degrees, while Mercury s obliquity is constant, almost zero. Differently from some authors, we will take Andoyer variables, in 3D space. Besides, w…

  Secular rotational dynamics of quasi-binary systems: Pluto-Charon, BP.MS

(Only some records are available in English at this moment)

• Abstract

  In the Nice model (Tsiganis et al 2005 - NiceI) it is accepted that the regular satellites survived to the planetary migration and the irregulars were captured after or during the migration itself. Nesvorný et al 2007 studied the capture process of irregular satellites during the phase of the planetary close encounters. In this work, the authors can successfully explain how Uranus and Nep…

  Capture of irregular satellites during the planetary migration, BE.EP.DR