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The near-equilibrium figure of the dwarf planet Haumea and possible mechanism of origin of its satellitesстатья
- Автор: Kondratyev B.P.
- Журнал: Astrophysics and Space Science
- Том: 361
- Номер: 5
- Год издания: 2016
- Издательство: Springer Nature
- Местоположение издательства: Switzerland
- DOI: 10.1007/s10509-016-2741-0
- Аннотация: Abstract The purpose of this paper consists in construct- ing the near-equilibrium model of the dwarf planet Haumea and developing the latent mechanism of accumulation of icy masses at sharp ends of the rapidly rotating planet. The model can be introduced by combining the ellipsoidal stone core with confocal icy shell and represents a non-uniform figure of rotating gravitating mass with superficial tension from the icy layer. We thoroughly study its dynamic proper- ties and achieve that the gravitational potential on an exter- nal and intermediate (between the core and the mantle) sur- faces was square-law function from coordinates. Using the new rigorous method we found that the thickness of an ice shell is equal to h ≈ 30 km, and its mass makes only 6.6 % from mass of a stone core. In absence of coherence between two surfaces of level, there is a growth of stresses and re- structuring the core and the shell. It is found that the dif- ference between angular velocities on both surfaces doesn’t exceed 6 %, which activates a special mechanism of relax- ation. The relaxation may lead to considerable (up to 10 %) lengthening the equatorial size of the body. This restructur- ing the shell leads to accumulation of icy masses at the sharp ends of the planet, which then separate from Haumea. For formation of two satellites of the planet Haumea it has been spent only 8 % from the mass of a shell. Before separation of satellites the planet Haumea was in near-equilibrium state, and its angular momentum was at 1.13 more, and the pe- riod of rotation was 16 m shorter and made T ≈ 3 . 64 h. The mechanism predicts that the orbits of satellites can not devi- ate much from the equatorial plane of Haumea. This is con- sistent with observations: indeed, the orbit of Namaka is al- most in the equatorial plane, and the orbit of massive Hi’iaka deviates only on 13°. The new mechanism can be useful also for studying the evolution of other ice-cover planets and satellites
- Добавил в систему: Кондратьев Борис Петрович