Rudolf Kippenhahn is author of very successful academic astronomy books as well of a large number of best-selling popular science books on astronomy, atomic physics and cryptology. From 1965-1975 he was professor for astronomy and astrophysics in Göttingen, Germany, and from 1975-1991 he was the director of the Max-Planck Institute for Astrophysics in Garching. He has received several medals and awards including the Eddington medal by the Royal Astronomical Society and the Karl-Schwarzschild medal of the Astronomische Gesellschaft. Alfred Weigert was professor for astrophysics at the University of Hamburg, Germany. His research forcussed on the simulation of stellar evolution and on the solution of the set of equations describing the structure of stars. He was not only Rudolf Kippenhahn’s co-author of the first edition of Stellar Structure and Evolution, but also author (with Heinrich J. Wendker) of the successful German introductory textbook “Astronomie und Astrophysik”. He died in 1992. Achim Weiss is an astrophysicist at the Max-Planck Instiute for Astrophysics in Garching and lecturer at the Ludwig-Maximilians University in Munich, Germany. Dr. Weiss’ research interests are on stellar evolution of low- and intermediate mass stars, population synthesis and AGB- and post-AGB evolution.