  TU Tau (= HD 38218 = HIP 27135) is a binary system consisting of a C-N carbon
star primary and an A-type secondary. We report on new photometry and
spectroscopy which tracked the recent disappearance of the A-star secondary.
The dimming of the A-star was gradual and irregular, with one or more brief
brightenings, implying the presence of nonhomogeneities in the carbon star
outflow. We also present evidence that the A-star is actively accreting
s-process enriched material from the carbon star and suggest that it will
therefore eventually evolve into a Barium giant. This is an important system as
well because the A-type star can serve as a probe of the outer atmosphere of
the carbon star.
