The Sun: A Very Short Introduction explores the science, structure, origins, workings, and future evolution of the Sun and solar physics, and its impact on life on earth. What are sunspots, and why do they form? What dynamic forces govern the Sun’s magnetic fields? Has the Sun grown brighter, smaller, or slower with age? Solar physics remains an observationally driven subject and determining cause and effect can be hampered by the Sun’s complexity. However, studying the Sun has led to remarkable discoveries in astronomy and basic physics, and recent technological developments and missions—some of which are already being deployed—will almost certainly improve our knowledge of the Sun, our nearest star.