Stars on the ascending helium giant branch I. From white dwarf merger to helium giant: the evolutionary state of the rapidly rotating hot subdwarf HE 1518-0948

M. Pritzkuleit, M. Dorsch, M. M. Miller Bertolami +3

Hot subdwarf stars with masses above $0.8M_{\odot }$ ascend the helium giant branch after the end of core helium burning, before entering the white dwarf cooling track or exploding a…