2018MNRAS.480.1211R

We discovered two bright DO-type white dwarfs, GALEX J053628.3+544854 (J0536+5448) and GALEX J231128.0+292935(J2311+2929), which rank among the eight brightest DO-type white dwarfs known. Our non-LTE model atmosphere analysis reveals effective temperatures and surface gravities of T_eff = 80000±4600 K and logg = 8.25±0.15 for J0536+5448 and T_eff = 69400±900 K and logg = 7.80±0.06 for J2311+2929. The latter shows a significant amount of carbon in its atmosphere (C=0.003^+0.005_–0.002, by mass), while for J0536+5448 we could derive only an upper limit of C < 0.003. Furthermore, we calculated spectroscopic distances for the two stars and found a good agreement with the distances derived from the Gaia parallaxes.