TheHubble Space TelescopeRevisits the Proper Motion of Pulsar B0656+14

We report the first successful measurement (with the Hubble Space Telescope Wide Field Planetary Camera 2) of a significant proper motion for an m V ~ 25 object, which we had proposed as the optical counterpart of the radio pulsar PSR B0656+14. The yearly displacement of 43 ± 2 mas is highly significant and, while in agreement with early rougher, radio measurements, stands out for its vastly improved accuracy. Together with Shearer and coworker's report of a possible optical pulsation, we regard this result as the final proof of the optical identification of PSR B0656+14.