No country for old stars -Spectroscopic confirmation of the first intermediate-age RR Lyrae in the open cluster Trumpler 5

Valentina D'Orazi, Cecilia Mateu, Giuliano Iorio +13

RR Lyrae stars are widely considered tracers of ancient (greater than 10 Gyr), metal-poor stellar populations. However, recent kinematic and photometric studies suggest the existen…