CEN 34 – high-mass YSO in M 17 or background post-AGB star?Zhiwei Chen, Dieter E. A. Nürnberger, Rolf Chini, Yao Liu, Min Fang and Zhibo JiangA&A, 557 (2013) A51DOI: https://doi.org/10.1051/0004-6361/201321694