This unique volume provides a complete reference on variable stars. It presents a wealth of typical light and colour curves (more than 200 in all) to allow identification, together with a detailed and up-to-date description of each subclass (giving the observational characteristics, historic background and current understanding of the astrophysical processes responsible for the variability). The editors, together with seven other world experts, have created a unique pictorial atlas of variable stars. In the first chapter they give a clear introduction to the nomenclature and classification of the light curves of variable stars, and to photometric systems and photometric accuracy. In the remaining chapters they provide a detailed account of each subclass of variable star in turn from eruptive, pulsating, rotating and cataclysmic variables, through to eclipsing binary systems and X-ray binaries. Specific variable stars, types and classes of variables, together with key astrophysical terms can be quickly and easily located in the book by means of detailed object-name and subject indexes. This comprehensive and up-to-date volume provides an essential reference for all those interested in variable stars - from researchers and graduate students through to dedicated amateurs.