Cepheid Metallicity in the Leavitt Law (C-MetaLL) survey: I. HARPS-N@TNG spectroscopy of 47 Classical Cepheid and 1 BL Her variables

V. Ripepi, G. Catanzaro, R. Molinaro +11

Classical Cepheids (DCEPs) are the most important primary indicators of the extragalactic distance scale. Establishing the dependence on metallicity of their period--luminosity and…