Principles of Astrophysics Using Gravity and Stellar Physics to Explore the Cosmos

This book is designed to show how physical principles can be used at the advanced undergraduate level to understand astronomical systems such as planets, stars, galaxies, and the universe as a whole. It emerges from a pair of courses at Rutgers Universitythat attract not just astrophysicsstudentsbut a broadaudienceof physics andengineeringstudents.Theorganizationistherefore“physics-?rst”:westartwith key principles of physics and then examine applications to astronomical systems. At Rutgers, each half of the book constitutes a coherent semester-length course; while there is a little overlap (notably with cosmology in Chaps.11 and 20), the two halves are largely independent and complementary. Part I focuses on gravity, because this is the dominant force in many astronomical systems and it governs many types of motions we observe. The goal of Chaps.2–11 is to develop a progressively richer understanding of gravity and the way astrophysicists use gravitational motion to investigatemass. Part IIcentersononeofthe“bigquestions”wehumansask.Whyare we here? is admittedly beyond the realm of physics, but a related question is within our reach: How did we come to be here? As the Sun was forming, various elements came togetherin the rightcombinationto forma rockyplanet with a tenuousatmosphere. On this planet Earth, the energy from the Sun and the gas in the atmosphere were just right to allow the emergenceof life. The energythat sustains us originates deep insideourstar,thanksto E Dmc2.Theatomsthatcompriseourbodieswereforged inpreviousgenerationsofstars.Literally,wearestardust.ThegoalofChaps.12–20 is to understandthe roles that electromagnetism as well as gas, atomic, and nuclear physics play in this remarkablestory