2002ApJ...580L.147M

We report on the proper-motion measurement of the proposed optical counterpart of the X-ray/radio pulsar PSR 1929+10. Using images obtained with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS; average epoch 2001.73), we computed a yearly displacement of +97±1 mas/yr in right ascension and +46±1 mas/yr in declination since the epoch (1994.52) of the original HST Faint Object Camera (FOC) detection. Both the magnitude and direction of the optical proper-motion components are found to be fully consistent with the most recent Very Long Baseline Array radio measurements. This result provides an unambiguous confirmation of the pulsar optical identification. In addition, we have used the combined STIS/FOC data sets to derive information on the pulsar spectrum, which seems characterized by a power-law component, apparently unrelated to the X-ray emission.