Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is de voted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documentation of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months: This time interval is near to that achieved by monthly abstracting journals, com pared to which our system of accumulating abstracts for about six months offers the advantage of greater convenience for the user. I, 1980; some older Volume 27 contains literature published in 1980 and received before August literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English.

"Astronomy and Astrophysics Abstracts" appearing twice a year has become oneof the fundamental publications in the fields of astronomy, astrophysics andneighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. The abstracts are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world.

The classification of stars into their various types is one of the fundamental areas of astronomy. This book is a comprehensive handbook on the tools, methods and results of stellar taxonomy. Although this subject is firmly rooted in classical astronomy, vast improvements in observational techniques have transformed the subject and greatly broadened the wavelength regions available for study. The first six chapters describe modern methods of spectroscopic and photometric classification. The remaining nine chapters describe particular families of stars, progressing from the hottest to the coolest. Within each category a description is given of the normal type and all the peculiar stars. Throughout the emphasis is on the phenomenology of classification, rather than the underlying astrophysics. Both authors have devoted themselves to developing the international centre for stellar data at Strasbourg, which uniquely qualifies them to write this definitive handbook for professional astronomers.