SIMBAD references

Multicolor photometry of the Vela pulsar (PSR B0833-45), updated by recent HST/WFPC2 observations obtained in the 555W, 675W and 814W filters, is presented. The available data provide the best characterization so far of the pulsar spectral shape, which is dominated by a flat power law continuum with spectral index α=-0.2±0.2, consistent with the extrapolation in the optical domain of the power law component of the X-ray spectrum detected by CHANDRA. In addition, a marginally significant dip (≃3σ) seems to be present at about 6500Å. Spectroscopic observations with the VLT, now in progress, will undoubtly provide a much better assessment of the reality and characteristics of this feature.