SIMBAD references

Hipparcos parallax measurements give a distance to the Wolf-Rayet WC8+O spectroscopic binary gamma^2 Vel of d=258^+41_-31 pc and a distance to the O4I(n)f star zeta Pup of d=429^+120_-77 pc. Adopting for gamma^2 Vel an interstellar extinction of A_v=0.06 mag, this implies an absolute magnitude M_v=-5.4 mag for the WC8+O binary system. Given that the binary components have a magnitude difference Delta m=1.4 mag, we derive M_v(WC8)=-3.7 and M_V(O)=-5.0 mag. The latter indicates an O8.5III rather than an O9I companion, as was adopted during the last 25 years. Apparently gamma^2 Vel is not a member of, but a foreground object before the open cluster Cr 173 and the association Vel OB2. Given a re-assessment of the distance of the Gum Nebula, gamma^2 Vel is still one of its ionizing sources, while zeta Pup appears to be located at the back of the Gum Nebula. Consequences of the Hipparcos distance determination of gamma^2 Vel for its mass, mass loss rate, luminosities at various wavelengths, and, briefly, its association with the Gum Nebula, are discussed.