Problems in Astrophysics

This edition has been fully restored with modern typesetting, custom cover design. Agnes M. Clerke's Problems in Astrophysics is a guided journey to the frontiers of modern astronomy, designed less to instruct than to awaken curiosity about the universe's unresolved riddles. Drawing on observatory work, photography, and spectroscopy, it moves from the Sun's chemistry, spectrum, sunspots, prominences, corona, and rotation into the wider physics of stars, nebulae, and the Milky Way. Clerke traces astrophysics from ancient mathematical astronomy to a newer science of physical reality, crediting Kepler and especially Francis Bacon with anticipating a true physical astronomy grounded in shared laws of nature. She shows how gravity, solar influence, magnetic cycles, and above all spectroscopy transformed the heavens from abstraction into matter, motion, and composition. Photography emerges as an indispensable partner to the sensitive plate, revealing faint phenomena, enabling precise celestial statistics, and extending study to stellar motion, nebulae, and close binaries through Doppler shifts. The book's rich survey of variable stars, clusters, temporary stars, and diverse nebulae presents a universe in active transformation. Yet Clerke also stresses the field's uncertainty: astrophysics must often extrapolate from extreme conditions. Her detailed treatment of eclipsing stars and Algol, the classic binary with a dark companion, exemplifies the discipline's power to uncover hidden stellar structure.