🔹 Title: Classical Cepheids and the study of the Milky Way (thin) disk

🔹 Speaker: Bertrand Lemasle (University of Heidelberg)

🔹 Abstract: The Pulsating variable stars like Cepheids and RR Lyrae are at the crossroads of stellar physics, Galactic archaeology, and cosmology. They occupy both ends of the range of stellar ages, RR Lyrae being older than 10 Gyr while classical Cepheids are young stars (<0.5 Gyr). Therefore, they provide important clues for the formation and evolution of young stellar systems, such as dwarf irregular galaxies like the Magellanic Clouds and the thin disk of large spiral galaxies like the Milky Way and Andromeda. In this talk, I will review recent results regarding the properties of the Milky Way thin disk obtained using classical Cepheids as tracers. Since distances of Cepheids can be derived with great accuracy, they allow us to investigate the structural properties of the Milky Way and I will report new insights on the warp of the disk and the location of the spiral arms. Moreover, the abundances of numerous alpha, iron-peak, and neutron-capture elements can be derived from the spectroscopic analysis of Cepheids. I will discuss recent technical improvements in the chemical analysis of Cepheids and their impact on Galactic abundance gradients, one of the best tools at our disposal to constrain chemo-dynamical evolutionary models.