  A new Hubble Space Telescope observation of the 7:4 resonant transneptunian
binary system (385446) Manw\"e has shown that, of two previously reported
solutions for the orbit of its satellite Thorondor, the prograde one is
correct. The orbit has a period of 110.18 $\pm$ 0.02 days, semimajor axis of
6670 $\pm$ 40 km, and an eccentricity of 0.563 $\pm$ 0.007. It will be viewable
edge-on from the inner solar system during 2015-2017, presenting opportunities
to observe mutual occultation and eclipse events. However, the number of
observable events will be small, owing to the long orbital period and expected
small sizes of the bodies relative to their separation. This paper presents
predictions for events observable from Earth-based telescopes and discusses the
associated uncertainties and challenges.
