Artículo de revista
The short rotation period of hi'iaka, haumea's largest satellite
Fecha
2016-12Registro en:
The Astronomical Journal, 152:195 (12pp), 2016 December
10.3847/0004-6256/152/6/195
Autor
Hastings, Danielle
Ragozzine, Darin
Fabrycky, Daniel
Burkhart, Luke
Fuentes González, Cesar
Margot, Jean-Luc
Brown, Michael
Holman, Matthew
Institución
Resumen
Hi’iaka is the larger outer satellite of the dwarf planet Haumea. Using relative photometry from the Hubble Space.Telescope and Magellan and a phase dispersion minimization analysis, we have identified the rotation period of Hi’iaka to be ∼9.8 hr (double peaked). This is ∼120 times faster than its orbital period, creating new questions about the formation of this system and possible tidal evolution. The rapid rotation suggests that Hi’iaka could have a significant obliquity and spin precession that could be visible in light curves within a few years. We then turn to an investigation of what we learn about the (currently unclear) formation of the Haumea system and family based on this unexpectedly rapid rotation rate. We explore the importance of the initial semimajor axis and rotation period in tidal evolution theory and find that they strongly influence the time required to despin to synchronous rotation, relevant to understanding a wide variety of satellite and binary systems. We find that despinning tides do
not necessarily lead to synchronous spin periods for Hi’iaka, even if it formed near the Roche limit. Therefore, the short rotation period of Hi’iaka does not rule out significant tidal evolution. Hi’iaka’s spin period is also consistent with formation near its current location and spin-up due to Haumea-centric impactors.