Hertzsprung–Russell diagram of the Galactic WC & WO stars with updated luminosities due to Gaia distances: The sample is taken from Sander et al. (2012), reduced to those with Gaia parallaxes that have a relative error of less then 40%. The vertical bars denote the error in luminosity resulting from the distance uncertainty. Tiny horizontal shifts have been applied to different different symbols for clarity. Stars with parallax errors of less than ten percent are represented by larger symbols. The zero age main sequence (ZAMS, from Ekström et al. 2012, here for stars without initial rotation) and for pure helium stars (He-ZAMS, from Langer 1989) are depicted as gray and green solid lines.