In section 7. Stellar structure and evolution
IRAS 11472−0800: an extremely depleted pulsating binary post-AGB star
Some of the lowest iron abundances are observed in post-AGB, but they were not born metal-poor. Their metal deficiency is the result of a gas-dust separation, likely happening when material is raining back onto the post-AGB star from a disc in a relatively wide binary system. IRAS 11472-0800, presented here, is among the most metal-poor objects of its class. Orbital radial velocity variations have been detected, but only longer-term monitoring will reveal the period.