Searching for He-rich post-AGB stars in clos binaries systems

他主导的后AGB明星的起源仍然不清楚。虽然非常晚的热脉冲情景可以解释以C为主的表面丰度，但没有一个单一的恒星演化情景能够解释以He为主的后AGB恒星。在之前的演化阶段，一个共同的包层被抛出，这可以解释这些恒星如何失去了富含氢的包层。利用中分辨率光谱学，我们的目标是测量有希望的近双星候选的径向速度漂移。这些系统的探测将为氦主宰的后AGB恒星的演化起源提供重要信息。

The origin of He-dominated post-AGB stars is still not understood. While very late thermal pulse scenarios can explain the C-dominated surface abundances, no single star evolutionary scenario is able to explain He-dominated post-AGB stars. The ejection of a common envelope in a previous evolutionary stage could explain how these stars have lost their hydrogen-rich envelope. With medium-resolution spectroscopy we aim to measure radial velocity shifts of promising close binary candidates. The detection of these systems would provide important information on the evolutionary origin of He-dominated post-AGB stars.