M. Stix: The Sun , 2002. Springer-Verlag Berlin and Heidelberg GmbH & Co. KG. ISBN: 3540428860 .
R. Rutten: The Generation and Transport of Radiation, 1991. (Fourth edition); You receive free copies during the lecture.
In addition, exercise sheets and printed handouts are part of the pensum.
Some topics have a rather compact discussion in the Stix book, alternative references to selected sections in Carroll & Ostlie will be given: Bradley W. Carroll, Dale A. Ostlie: An Introduction to Modern Astrophysics, 2007. Addison-Wesley Publishing Company, Inc.