Depending on your mathematical background, different resources may be more suitable: Astronomy: A Free, Online Astro 101 Textbook
: The internal structure of stars, nuclear fusion reactions, and the life cycles of stars—from formation to remnants like white dwarfs, neutron stars, and black holes. Introductory Astronomy and Astrophysics
: Understanding the electromagnetic spectrum, photometry, and how light reveals the temperature, mass, and composition of stars. Depending on your mathematical background
