Stellar and Galactic Astronomy Credit Hours: 3 hours. The study of the sun and stars, their physical properties and evolution, interstellar matter, star clusters, our galaxy and other galaxies, and the origin and evolution of the Universe. Offered fall and spring semester every year. Duplicate Credit: Not open to students with credit in ASTR 1120, ASTR 1120H Semester Offered: Fall Spring Level: Undergraduate