  HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV)
trend indicative of a massive companion on a wide orbit. Here we present direct
images of the source responsible for the trend using the Magellan Adaptive
Optics system. We detect the object (HD 11112B) at a separation of 2\fasec 2
(100 AU) at multiple wavelengths spanning 0.6-4 \microns ~and show that it is
most likely a gravitationally-bound cool white dwarf. Modeling its spectral
energy distribution (SED) suggests that its mass is 0.9-1.1 \msun, which
corresponds to very high-eccentricity, near edge-on orbits from Markov chain
Monte Carlo analysis of the RV and imaging data together. The total age of the
white dwarf is $>2\sigma$ discrepant with that of the primary star under most
assumptions. The problem can be resolved if the white dwarf progenitor was
initially a double white dwarf binary that then merged into the observed
high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object
that can be used to calibrate atmospheric and evolutionary models of cool white
dwarfs and should thus continue to be monitored by RV and direct imaging over
the coming years.
