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We present the very long baseline interferometry H2O maser monitoringobservations of the red supergiant, PZ Cas, at 12 epochs from 2006 April to2008 May. We fitted maser motions to a simple model composed of a common annualparallax and linear motions of the individual masers. The maser motions withthe parallax subtracted were well modeled by a combination of a common stellarproper motion and a radial expansion motion of the circumstellar envelope. Weobtained an annual parallax of 0.356+/-0.026 mas and a stellar proper motion of{\mu}*{\alpha}cos{\delta}=-3.7+/-0.2 and {\mu}*{\delta}=-2.0+/-0.3 mas/yreastward and northward, respectively. The annual parallax corresponds to atrigonometric parallax of 2.81+0.22-0.19 kpc. By rescaling the luminosity of PZCas in any previous studies using our trigonometric parallax, we estimated thelocation of PZ Cas on a Hertzsprung-Russell diagram and found that itapproaches a theoretically evolutionary track around an initial mass of~25M(sun). The sky position and the distance to PZ Cas are consistent with theOB association, Cas OB5, which is located in a molecular gas super shell. Theproper motion of PZ Cas is close to that of the OB stars and other redsupergiants in Cas OB5 measured by the Hipparcos satellite. We derived thepeculiar motion of PZ Cas of Us = 22.8+/-1.5, Vs = 7.1+/-4.4, and Ws =-5.7+/-4.4 km/s. This peculiar motion has rather a large Us component, unlikethose of near high-mass star-forming regions with negatively large Vs motions.The uniform proper motions of the Cas OB5 member stars suggest random motionsof giant molecular clouds moving into local potential minima in atime-dependent spiral arm, rather than a velocity field caused by the spiralarm density wave.

Distance and Proper Motion Measurement of the Red Supergiant, PZ Cas, in Very Long Baseline Interferometry H2O Maser Astrometry