Astrophysics: Decoding the Cosmos is an accessible introduction to the key principles and theories underlying the subject. It takes a close look at the radiation and particles that we receive from astronomical objects and provides a thorough understanding of what these information-bearers tell us. Chapters are dedicated to complex physical processes described in an accessible manner and pull together relevant background material that , with many examples, places the physics firmly into an astronomical context. * an accessible student-friendly guide to the key theories and principles of astrophysics * includes numerous illustrations, examples and end-of-chapter problems to enhance student understanding * focuses on the 'how' of astronomy- how densities, temperatures, masses and energies are actually determined * a 'tool chest' for undergraduate astronomers providing key background information to the subject * describes the physics first, then moves on to provide examples of the theory in practice This book will be invaluable for students taking courses in astrophysics, physics and astronomy and will also be a useful reference for graduate students looking for an overview of the subject.