The book contains courses taught to a public of Ph. D. students, post-docs and con?rmed researchers in all ?elds of heliospheric plasma physics. It aims at identifying physical issues which are common to two di?erent ?elds of astr- omy: solar and magnetospheric physics. Emphasis is given to basic processes of transport and conversion of energy: magnetic reconnection is discussed in detail from the viewpoints of MHD and kinetic physics. Processes of charged particle acceleration are reviewed and confronted with recent observations. The subject is introduced by a summary of MHD and the basic structures and parameters of the solar atmosphere, terrestrial ionosphere and mag- tosphere are reviewed. The book combines a pedagogic and comprehensive presentation of physical issues and raises fully open questions, with the c- plementary and sometimes con?icting views of geophysicists and solar phy- cists. The book's focus, while basic, opens new avenues. Observatory of Meudon, France Ludwig Klein IAS, Orsay, France Jean-Claude Vial OCA, France Jean-Pierre Rozelot August 2000 The Editors Preface Following the great success of the ?rst two CNRS Summer Schools on Solar Astrophysics held in Oleron (May 1996 and May 1997 - two schools devoted to the highlights of solar physics), I came to the conclusion that the initiative should be continued."

The advent of modern techniques of observation in the world of amateur astronomers increases their potential to participate efficently to scientific programs. In particular, spectrography is a new, quickly developing tool for amateur astronomers. Moreover, amateur astronomers have more and more possibilities to access telescopes with diameters above 50 cm, either in professional observatories or belonging to associations. These improvements allow professional and amateurs to undertake fruitful collaborations and common meetings. This book collects the lectures given by professional for amateur astronomers during a CNRS school. It focuses on spectroscopy, a budding domain for amateurs already extensively used by professionals. Basic principles of spectroscopy are described in a clear and precise way and applications to the Sun, Be stars, nebulae, and comets are successively exposed. A chapter is dedicated to the analysis of spectral data, to put practical spectroscopy within reach of amateur astronomers.