2692 20160701171709.0 10.1051/eas/1571062 DOI ASTROimport-849 Lobel, A. 2015 Yellow Hypergiants: A Comparative Study of HR 5171A, Rho Cas, and HR 8752 We present a comparative study of the detailed spectroscopic variability of selected Fe i absorption lines observed between 1991 and 1995 in the optical spectra of the bright yellow hypergiants HR 5171A and Rho Cas. We also compare with the high-resolution spectrum of HR 8752. The three cool hypergiants reveal broad lines with very similar shapes. The variations with time in the line shapes and depths of HR 5171A and Rho Cas are very similar. The spectroscopic variability is caused by quasi-periodic atmospheric pulsations that strongly correlates with the observed radial velocity and V-brightness changes. de Jager, C. Nieuwenhuijzen, H. van Genderen, A. M. Oudmaijer, R. EAS Publications Series 71 2015 279-280 http://esoads.eso.org/abs/2015EAS....71..279L published in NONREF