This is the latest effort in a sequence of presentations begun in 1949 with a series of lectures on long-focus photographic astrometry given by the author as Fulbright professor in Paris at the invitation by the late H.
Interest world-wide in the provision of new observational astro- nomical facilities in the form of ground-based optical telescopes of large aperture has never been higher than exists at present.
The symposium on "e;Neutral Clouds near HII Regions"e; was prompted by an obvious need to bring together workers specifically interested in the dynamical and photochemical effects in regions showing clear evidence of on-going star formation.
When we first approached some colleagues allover the world to sound them about a volume dedicated to Professor John Xanthakis on the occasion of completing twenty-five years of scientific activities as fellow of the National Academy of Athens, any possible doubts as to the feasibility of the project were quickly dispelled by their warm and encouraging response.
Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave- lengths.
This work deals with some of the most typical complexes of interstellar matter and is intended to serve both as a reference book for the specialist and as an introduction for the newcomer to the field.
The purpose of this book is to give a detailed description of the planetary nebulae including the relevant astronomical observations and their interpretation.
Problems associated with a general scarcity of observations of the southern sky have persisted since the present era of galactic research began some sixty years ago.
This book contains the invited and contributed lectures presented at a meeting organised in the context of the XVIII general assembly ofthe IAU, held in Patras, August 19, 1982.
Attilio Ferrari I want to recall here the basic points I raised at the beginning of the Workshop as the main targets of discussion (in the name of the Scientific Committee).
The idea of holding this workshop on "e;The Jllilky Way"e; arose at the conference dinner of a meeting on "e;Regions of Recent Star Formation"e; held at Penticton in June 1981.
The large-scale structure of the Universe and systems Clusters, and Groups of galaxies are topics like Superclusters, They fully justify the meeting on "e;Clusters of great interest.
The idea of holding a colloquium on Schmidt telescopes (techniques and science) originated from the observation that, in the last ten years and in spite of the remarkable developments and achievements in this field of astronomical research, there had been no specific opportunity for the experts to meet together, make the point on the state of the art, discuss and coordinate future plans.
The book aims to present current knowledge concerning the propagation of electro- magnetic waves in a homogeneous magnetoplasma for which temperature effects are unimportant.
This volume is the product of Lecturers in the fourth Course of the International School of Cosmic-Ray Astrophysics held at the Ettore Majorana Center in Erice, Sicily in November, 1984.
Investigation of the interplanetary dust cloud is characterized by contributions from quite different methods and fields, such as research on zodiacal light, meteors, micrometeoroids, asteroids, and comets.
