MUSELLA, ILARIAILARIAMUSELLA2020-04-282020-04-282016978-3-319-19329-81570-6591http://hdl.handle.net/20.500.12386/24263Classical Cepheids plays a key role in the calibration of the extragalactic distance scale. In spite of their importance, some uncertainties related to their properties remain. In particular, a general consensus on the possible dependence on the metallicity of the host galaxy of the Cepheid properties has not been reached yet. These uncertainties could produce significant systematic errors in the calibration of the secondary distance indicators we need to reach cosmologically significant distances and in turn in the evaluation of the Hubble constant H <SUB>0</SUB>. Possible solutions are discussed.STAMPAenConference paper10.1007/978-3-319-19330-4_112-s2.0-84979021455000389802600012https://link.springer.com/content/pdf/10.1007%2F978-3-319-19330-4_11.pdf2016ASSP...42...79MFIS/05 - ASTRONOMIA E ASTROFISICAScienze Fisiche Settori ERC (ERC) di riferimento::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation