ARE THE CEPHEIDS IN IC-4182 DIFFERENT FROM POPULATION-I CEPHEIDS IN THE GALAXY

Recently, the Cepheids in the spiral galaxy IC 4182 have been in the s potlight due to their use as calibrators for the supernova la distance scale. In this process the distance to IC 4182 is obtained by applyin g the local Population I period-luminosity relation to the IC 4182 Cep heid sample. But is it really appropriate to do so? We employ the tech nique of Fourier decomposition to compare the light curves of long-per iod Cepheids in IC 4182 with those of their Population I counterparts in the Galaxy. At the level of precision of the current data, no diffe rence is apparent between the two groups. On the other hand, both grou ps have light curves which seem distinct from those of a number of Pop ulation II Cepheids in the Galaxy. Accordingly, we find no reason why the local period-luminosity relation should not be used to infer the d istance to IC 4182.