The mass, orbit, and tidal evolution of the QuaoarWeywot system
Abstract
Here we present new adaptive optics observations of the QuaoarWeywot system. With these new observations we determine an improved system orbit. Due to a 0.39 day alias that exists in available observations, four possible orbital solutions are available with periods of ∼11.6, ∼12.0, ∼12.4, and ∼12.8 days. From the possible orbital solutions, system masses of 1.31.5 ± 0.1 × 10^{21} kg are found. These observations provide an updated density for Quaoar of 2.75.0 g cm^{3}. In all cases, Weywot's orbit is eccentric, with possible values ∼0.130.16. We present a reanalysis of the tidal orbital evolution of the QuaoarWeywot system. We have found that Weywot has probably evolved to a state of synchronous rotation, and has likely preserved its initial inclination over the age of the Solar System. We find that for plausible values of the effective tidal dissipation factor tides produce a very slow evolution of Weywot's eccentricity and semimajor axis. Accordingly, it appears that Weywot's eccentricity likely did not tidally evolve to its current value from an initially circular orbit. Rather, it seems that some other mechanism has raised its eccentricity postformation, or Weywot formed with a nonnegligible eccentricity.
 Publication:

Icarus
 Pub Date:
 January 2013
 DOI:
 10.1016/j.icarus.2012.11.004
 arXiv:
 arXiv:1211.1016
 Bibcode:
 2013Icar..222..357F
 Keywords:

 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 Accepted to Icarus, Nov. 8 2012