Physical modeling of triple near-Earth Asteroid (153591) 2001 SN263 from radar and optical light curve observations

We present physical models of the three components of the asteroid system. We constrain the primary's pole direction to an ecliptic longitude and latitude of (309°,-80°)±15°. We find that the primary rotates with a period 3.4256±0.0002h and that the larger satellite has a rotation period of 13.43±0.01h, considerably shorter than its orbital period of approximately 6 days. We find that the rotation period of the smaller satellite is consistent with a tidally locked state and therefore rotates with a period of 0.686±0.002 days (Fang et al. [2011]. Astron. J. 141, 154-168). The primary, the larger satellite, and the smaller satellite have equivalent diameters of 2.5±0.3km, 0.77±0.12km, 0.43±0.14km and densities of 1.1±0.2g/cm3,1.0±0.4g/cm3,2.3±1.3g/cm3, respectively.