The white dwarf binary pathways survey – VIII. A post-common envelope binary with a massive white dwarf and an active G-type secondary star

ABSTRACT The white dwarf binary pathways survey is dedicated to studying the origin and evolution of binaries containing a an intermediate-mass secondary star spectral type A, F, G, or K (WD + AFGK). Here, we present CPD-65 264, new post-common envelope with orbital period 1.37 d that contains massive ($0.86\pm 0.06\, \mathrm{M}_{\odot }$) ($1.00\pm 0.05\, main-sequence star. We characterized measured using high-resolution optical spectroscopy. parameters are determined from HST In addition, TESS observations revealed up 19 per cent surface covered starspots. Small changes found in light curve indicate second example G-type latitudinal differential rotation. Given relatively large mass short period, future transfer will be dynamically thermally stable system evolve into cataclysmic variable. formation can understood assuming common without contributions energy sources besides energy. 264 seventh secondaries small efficiency equation, agreement findings for M-dwarf substellar companions.