Emphasizing the underlying unity of all astronomical observations, Astrophysical Techniques provides a coherent state-of-the-art account ofthe instruments and techniques used in current astronomy and astrophysics. The fifth edition of this well-respected text includes many new instruments and techniques while removing some that have long been unused by both professional and amateur astronomers. This edition presents a new, brief discussion on the invention and development of the telescope, a new section that describes the attempts to detect dark matter and dark energy, and extended and updated discussions on computer, Internet, and spacecraft-based observations and research.