Welcome to the Companion Website for An Introduction to Modern Astrophysics, An Introduction to Modern Stellar Astrophysics, and An Introduction to Modern Galactic Astrophysics and Cosmology, Second Edition. On this site, you will find online resources for all three texts including weblinks, data sets, sources codes, and images from the book. To get started, please choose "Astrophysics 2e Online Resources" from the menu above.