No CrossRef data available.
Published online by Cambridge University Press: 12 April 2016
Comments in the literature in recent years reveal a variety of misconceptions about the role and value of galactic clusters for calibrating the Cepheid period-luminosity-colour (PLC) relation. This paper attempts to clarify some of these points using personal experiences gained from studies of the sparse galactic clusters and groups in which some classical Cepheids are located.
Reddening is often blamed for problems originating from other causes. Three features of reddening are sometimes overlooked: (i) no universal reddening law applies to all fields, (ii) mean reddening laws are not applicable to samples of dispersed objects, and (iii) patchy extinction is the norm.