We study all aspects of the Sun, our nearest star. 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 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). We also discuss data analysis of recent transits of Mercury across the face of the Sun and the June 8 2004, transit of Venus, the first transit of Venus since 1882. Students will meet weekly with the professor in groups of two or three to discuss readings and present short papers. Format: tutorial. Evaluation will be based on four 5-page papers, discussions, and presentations. Students will be expected to improve their writing throughout the course, with the aid of careful editing by and comments from the professor. Prerequisites: Astronomy 111 (or Astronomy 101 and either 102 or 104 with permission of instructor) and a 200-level Physics or Astronomy course. Enrollment limit: 12 (expected: 10).