  V1094 Tau is bright eclipsing binary star with an orbital period close to 9
days containing two stars similar to the Sun. Our aim is to test models of
Sun-like stars using precise and accurate mass and radius measurements for both
stars in V1094 Tau. We present new spectroscopy of V1094 Tau which we use to
estimate the effective temperatures of both stars and to refine their
spectroscopic orbits. We also present new, high-quality photometry covering
both eclipses of V1094 Tau in the Stroemgren uvby system and in the Johnson
V-band. The masses, radii and effective temperatures of the stars in V1094 Tau
are found to be M$_A$ = 1.0965 $\pm$ 0.0040 M$_{\odot}$, R$_A$ = 1.4109 $\pm$
0.0058 R$_{\odot}$, T$_{\rm eff,A}$ = 5850 $\pm$ 100 K, and M$_B$ = 1.0120
$\pm$ 0.0028 M$_{\odot}$, R$_B$ = 1.1063 $\pm$ 0.0066 R$_{\odot}$, T$_{\rm
eff,B}$ = 5700 $\pm$ 100 K. An analysis of the times of mid-eclipse and the
radial velocity data reveals apsidal motion with a period of 14500 $\pm$ 3700
years. The observed masses, radii and effective temperatures are consistent
with stellar models for an age $\approx$ 6 Gyr if the stars are assumed to have
a metallicity similar to the Sun. This estimate is in reasonable agreement with
our estimate of the metallicity derived using Stroemgren photometry and
treating the binary as a single star ([Fe/H] $= -0.09 \pm 0.11$). The rotation
velocities of the stars suggest that V1094 Tau is close to the limit at which
tidal interactions between the stars force them to rotate pseudo-synchronously
with the orbital motion.
