On the Color–Metallicity Relation of the Red Clump and the Reddening toward the Magellanic Clouds

Abstract The zero point of the reddening toward Large Magellanic Cloud (LMC) has been subject some dispute. Its uncertainty propagates as a systematic error for methods that measure extragalactic distance scale through knowledge absolute extinction LMC stars. In an effort to resolve this issue, we used three different calibrate most widely metric predict extinction, intrinsic color red clump, ( V ? I ) RC ,0 , inner ?3° galaxy. first approach was empirically points BaSTI isochrones over wide metallicity range ?[Fe/H] ? 1.10 using measurements clump stars in 47 Tuc, solar neighborhood, and NGC 6791. From these efforts, also properties neighborhood G BP K s RP J H M Ks = (1.02, 2.75, 2.18, 1.52, 0.64, 0.15, ?0.23, ?1.63). second third were compare observed colors those Cepheids RR Lyrae LMC. With methods, estimated be ,0,LMC {? 0.93 0.91 ± 0.02, 0.89 0.02}, respectively, similarly, ,0,SMC 0.85 0.84 Small Cloud. We estimate luminosities ,LMC ?0.26 ,SMC ?0.37. show important implications recent calibrations tip giant branch Clouds 0 .