Unraveling the complex dynamics of Haumea’s satellites

Almost all of the largest transneptunian objects (TNOs) have satellites which are thought to have formed in the aftermath of collisions. Understanding the orbits of these satellites can provide detailed information about their physical characteristics, formation, and tidal evolution. One of the most intriguing TNO satellite systems is the Haumea system, with two relatively massive satellites, Hi’iaka and Namaka. For over a decade, this system has defied explanation. A variety of orbital fitting techniques have failed to provide a single self-consistent orbit fit to the decade worth of precise HST observations. However, using a new orbit fitting tool, combined with a reanalysis of the observations, we have found a fully self-consistent orbital model for the Haumea system. This orbital model provides tight constraints on the masses of the satellites, the spin pole of Haumea, and the non-spherical shape of Haumea’s gravitational field. Here, we present this new orbital model and discuss its implications for our understanding of Haumea’s formation and evolution.