  HD 181068 is the brighter of the two known triply eclipsing hierarchical
triple stars in the Kepler field. It has been continuously observed for more
than 2 years with the Kepler space telescope. Of the nine quarters of the data,
three have been obtained in short-cadence mode, that is one point per 58.9 s.
Here we analyse this unique dataset to determine absolute physical parameters
(most importantly the masses and radii) and full orbital configuration using a
sophisticated novel approach. We measure eclipse timing variations (ETVs),
which are then combined with the single-lined radial velocity measurements to
yield masses in a manner equivalent to double-lined spectroscopic binaries. We
have also developed a new light curve synthesis code that is used to model the
triple, mutual eclipses and the effects of the changing tidal field on the
stellar surface and the relativistic Doppler-beaming. By combining the stellar
masses from the ETV study with the simultaneous light curve analysis we
determine the absolute radii of the three stars. Our results indicate that the
close and the wide subsystems revolve in almost exactly coplanar and prograde
orbits. The newly determined parameters draw a consistent picture of the system
with such details that have been beyond reach before.
