The distance to the Vela pulsar ( PSR B0833 - 45 ) has been traditionally assumed to be 500 pc .
Although affected by a significant uncertainty , this value stuck to both the pulsar and the SNR .
In an effort to obtain a model free distance measurement , we have applied high resolution astrometry to the pulsar V \sim 23.6 optical counterpart .
Using a set of five HST/WFPC2 observations , we have obtained the first optical measurement of the annual parallax of the Vela pulsar .
The parallax turns out to be 3.4 \pm 0.7 mas , implying a distance of 294 ^ { -50 } _ { +76 } pc , i.e .
a value significantly lower than previously believed .
This affects the estimate of the pulsar absolute luminosity and of its emission efficiency at various wavelengths and confirms the exceptionally high value of the N _ { e } towards the Vela pulsar .
Finally , the complete parallax data base allows for a better measurement of the Vela pulsar proper motion ( \mu _ { \alpha } cos ( \delta ) = -37.2 \pm 1.2 mas yr ^ { -1 } ; \mu _ { \delta } = 28.2 \pm 1.3 mas yr ^ { -1 } after correcting for the peculiar motion of the Sun ) which , at the parallax distance , implies a transverse velocity of \approx 65 km sec ^ { -1 } .
Moreover , the proper motion position angle appears specially well aligned with the axis of symmetry of the X-ray nebula as seen by Chandra .
Such an alignment allows to assess the space velocity of the Vela pulsar to be 81 km sec ^ { -1 } .