In the past decade, indirect (Doppler) imaging techniques have opened up a whole new discipline in stellar astronomy, providing increasingly detailed photometric, magnetic, and chemical inhomogeneity images of stellar surfaces. Furthermore, new optical interferometers are already being used with sophisticated interferometer techniques to image stellar surface structures more directly, and in the future the ESO VLT Interferometer and other instruments will extend these capabilities enormously. These developments are highlighted in the first two sections of this book. The large number of recent results, ground-based and space-based, and the lack of a generally accepted dynamo theory with predictive power for the stars and the Sun, result in an ever-growing complexity of interpretation of individual results. The IAU Symposium 176 on Stellar Surface Structure' consequently focused on spatially resolved stellar observations throughout the H-R diagram, from O- and B-stars to late M-stars. Two further sections in this book summarize the current observational data on surface inhomogeneities in stellar photospheres, chromospheres, and coronae. Finally, a special section is devoted to next generation model atmospheres.

In the past decade, indirect (Doppler) imaging techniques have opened up a whole new discipline in stellar astronomy, providing increasingly detailed photometric, magnetic, and chemical inhomogeneity images of stellar surfaces. Furthermore, new optical interferometers are already being used with sophisticated interferometer techniques to image stellar surface structures more directly, and in the future the ESO VLT Interferometer and other instruments will extend these capabilities enormously. These developments are highlighted in the first two sections of this book. The large number of recent results, ground-based and space-based, and the lack of a generally accepted dynamo theory with predictive power for the stars and the Sun, result in an ever-growing complexity of interpretation of individual results. The IAU Symposium 176 on Stellar Surface Structure' consequently focused on spatially resolved stellar observations throughout the H-R diagram, from O- and B-stars to late M-stars. Two further sections in this book summarize the current observational data on surface inhomogeneities in stellar photospheres, chromospheres, and coronae. Finally, a special section is devoted to next generation model atmospheres.

Die Sonne ist ein ziemlich durchschnittlicher Stern, der sich vor allem durch seine geringe Entfernung zur Erde auszeichnet. Bei naherer Betrachtung entpuppt sich die Sonnenoberflache jedoch als wahrer "Hexenkessel" mit Magnetfeldern aller Art, Sonnenflecken, Plasmaeruptionen und plotzlichen Explosionen, die alle einen fundamentalen Einfluss auf unseren Planeten haben, einen Einfluss, den wir erst mit modernster Astronomie messen und verstehen gelernt haben. Dieses Buch erklart die spannenden Innenwelten, die physikalischen Grundlagen und Funktionsweisen der Sonne und der anderen aktiven Sterne. Die aktuellsten Forschungsergebnisse und neuestes Datenmaterial werden fundiert, aber auch fur Laien verstandlich, aufbereitet und mit uber 200 Bildern, teilweise Aufnahmen mit dem Hubble Weltraumteleskop, illustriert."