Reviews in Modern Astronomy

The fourth yearbook of the Astronomische Gesellschaft contains 18 contributions mostly on solar physics and solar system problems, the results of the Hipparcos and ROSAT space missions, and supernova 1987A, together with Eugene Parker's Schwarzschild Lecture.

Convection, Spontaneous Discontinuities, and Stellar Winds and X-Ray Emission.- The Sun as a Prototype in the Study of Stellar Magnetic Activity.- Hydrodynamics of the Solar Photosphere: Model Calculations and Spectroscopic Observations.- Solar Spectroscopy with a 100 x 100 Diode Array.- Solar Research at Potsdam: Papers on the Structure and Dynamics of Sunspots.- Time-Resolved Stokes V Polarimetry of Small-Scale Magnetic Structures on the Sun.- Instabilities in Astrophysical Shear Flows.- Simultaneous Observations with a Tunable Filter and the Echelle Spectrograph of the Vacuum Tower Telescope at Tenerife.- Aspects of the Present Heliospheric Research.- Turbulence in the Solar Wind.- Dust Rings Around Planets.- Asteroid-Asteroid Interactions - Dynamically Irrelevant?.- First Results from the X-Ray Astronomy Mission ROSAT.- TYCHO/HIPPARCOS A Successful Mission! First Results and Further Improvements.- Shock Waves in Accretion Disks.- Magnetic Field Measurements on Cool Stars.- The Expanding Envelope of Supernova 1987A in the Large Magellanic Cloud.- Dynamos in Galaxies.- Index of Contributors.