Position of our four stars (magenta stars) in the T_eff−log g diagram compared to other hydrogen-rich sdBs and sdOs and evolutionary tracks. The post-EHB tracks are from the Y = 0.288 set of Dorman et al. (1993) for total masses of 0.471, 0.473, 0.475, 0.480, and 0.485 M_⊙ from left to right. An additional post-early AGB track is also illustrated (dashed 0.495 M_⊙). The red lines define the EHB region where core helium burning takes place. Observed data are from subsamples of H-rich stars taken from Fontaine et al. (2014, asterisk) and Stroeer et al. (2007, circle). Also included are the position of three other sdOs for which chemical abundances are known (AA Dor, Feige 110, and BD+28°4211) as well as EC 11481−2303 and CPD−71°172B (magenta filled circles).