Proper Motion Measurements of Pulsar B1951+32 in the Supernova Remnant   CTB 80
  Using the Very Large Array and the Pie Town antenna, we have measured the position of the radio pulsar B1951+32 relative to nearby background radio sources at four epochs between 1989 and 2000. These data show a clear motion for the pulsar of (25 +/- 4) milliarcsec/yr at a position angle (252 +/- 7) degrees (north through east), corresponding to a transverse velocity (240 +/- 40) km/s for a distance to the source of 2 kpc. The measured direction of motion confirms that the pulsar is moving away from the center of its associated supernova remnant, the first time that such a result has been demonstrated. Independent of assumptions made about the pulsar birth-place, we show that the measured proper motion implies an age for the pulsar of (64 +/- 18) kyr, somewhat less than its characteristic age of 107 kyr. This discrepancy can be explained if the initial spin period of the pulsar was (27 +/- 6) ms. 
J. M. Migliazzo (1), B. M. Gaensler (1 and 2), D. C. Backer (3), B. W.   Stappers (4), E. van der Swaluw (5) and R. G. Strom...