Absolute Proper Motion of IRAS 00259+5625 with VERA : Indication of
  Superbubble Expansion Motion
  We present the first measurement of the absolute proper motions of IRAS
00259+5625 (CB3, LBN594) associated with the HI loop called the "NGC281
superbubble" that extends from the Galactic plane over ~300 pc toward
decreasing galactic latitude. The proper motion components measured with VERA
are (mu_alpha cos(delta), mu_delta) = (-2.48 +/- 0.32, -2.85 +/- 0.65) mas
yr^{-1}, converted into (mu_l cos(b), mu_b) = (-2.72 +/- 0.32, -2.62 +/- 0.65)
mas yr^{-1} in the Galactic coordinates. The measured proper motion
perpendicular to the Galactic plane (mu_b) shows vertical motion away from the
Galactic plane with a significance of about ~4-sigma. As for the source
distance, the distance measured with VERA is marginal, 2.4^{+1.0}_{-0.6} kpc.
Using the distance, an absolute vertical motion (v_{b}) of -17.9 +/- 12.2 km
s^{-1} is determined with ~1.5-sigma significance. The tendency of the large
vertical motion is consistent with previous VLBI results for NGC 281 associated
with the same superbubble. Thus, our VLBI results indicate the superbubble
expansion motion whose origin is believed to be sequential supernova
explosions.
