First direct detection of an RR Lyrae star conclusively associated with an intermediate-age cluster

Cecilia Mateu, Bolivia Cuevas-Otahola, Juan José Downes

RR Lyrae stars have long been considered unequivocal tracers of old (>10 Gyr) and metal-poor ($[Fe/H]<-0.5$) stellar populations. First, because these populations are wher…