We study all aspects of the Sun, our nearest star, as we approach the maximum of the sunspot cycle. We discuss the interior, including the neutrino experiment and helioseismology, the photosphere, the chromosphere, the corona, and the solar wind. We discuss the Sun as an example of stars in general. We discuss both theoretical aspects and observational techniques, including work at the recent total solar eclipses. We discuss results from current spacecraft, including the Solar and Heliospheric Observatory (SOHO) and the Transition Region and Coronal Explorer (TRACE). Students will meet weekly with the professor in groups of two or three to discuss readings, solve problems, and present short papers. Evaluation will be based on one hour exam, discussions, problem sets, presentations, and a final exam or paper. Prerequisites: Astronomy 111 (or Astronomy 101 and either 102 or 104 with permission) and a 200-level Physics or Astronomy course. Open to juniors and seniors. This course is writing intensive.