The Astrophysics Major

The Astrophysics major will be elected by students who plan graduate study in astronomy, astrophysics, or a closely related field, and also can be elected by those interested in a wide variety of careers. This major emphasizes the description of the universe and its constituents in terms of physical processes.

Potential Astrophysics majors should consult early with members of the Department of Physics and Astronomy to determine their most appropriate route to and through the major. An essential ingredient in such students’ undergraduate training is experience in physics and mathematics. Therefore, the major normally will begin in the first year a student is at Williams with Physics 131 or 141 or 151 and Math 140 in the fall continuing with Physics 142 and Math 150/151 in the spring. Students with very good backgrounds placing them out of Physics 142 may elect Physics 201 instead. Astronomy 111 could therefore be taken in the sophomore year, however exceptionally motivated students can consider taking it their first semester at Williams along with physics and math. Faculty are always glad to advise students as they plan their courses.

In addition to the major courses described below, other courses in geosciences, mathematics, and computer science may also be appropriate.

Major Requirements for Astrophysics


           or Astronomy 101: Stars: From Suns to Black Holes and either Astronomy 102: The Solar System – Our Planetary Home or Astronomy 104: The Milky Way Galaxy and the Universe Beyond

                     (In other words, a student may take Astronomy 111 for the major, but if they take Astronomy 101 instead of Astronomy 111 then they must also take one of Astronomy 102 or 104.)

    • Physics 131: Particles and Waves or Physics 141: Particles and Waves–Enriched or equivalent placement
    • Physics 142: Foundations of Modern Physics or Physics 151: Seminar on Modern Physics
    • Physics 201: Electricity and Magnetism
    • Physics 202: Waves and Optics
    • Physics 301: Introductory Quantum Physics
    • Math 150/151: Multivariable Calculus
    • Physics 210 or Math 209: Mathematical Methods for Scientists
    • Three 400-level Astronomy courses or Two 400-level Astronomy courses and one of the following:
      • Astronomy 211: Observation and Data Reduction Techniques in Astronomy
      • Physics 302: Statistical Physics
      • Physics 402: Applications of Quantum Mechanics
      • Physics 405: Electromagnetic Theory
      • Physics 411: Classical Mechanics
      • Physics 418: Gravity

The total number of courses required for the Astrophysics major, an interdisciplinary major, is eleven. Students entering with Advanced Placement in physics and/or math may obtain credit toward the major for the equivalent of Physics 142 and/or Math 150 taken elsewhere, but at least 8 courses in astronomy, physics, and math must be taken at Williams. There are some aspects of astrophysics that are closely related to chemistry or geology. In recognition of this relation, certain advanced courses in those departments can be accepted for credit toward the Astrophysics major on a two-for-one basis.

The Degree with Honors in Astrophysics

The honors degree in Astrophysics will be awarded on the basis of a senior thesis presenting the results of an original observational, experimental, or theoretical investigation carried out by the student under the direction of a faculty member in the Department of Physics and Astronomy. There are no specific grade requirements (other than College-wide requirements for remaining in good academic standing) for entry into the thesis research program; however, a student wishing to do a thesis should have demonstrated both ability and motivation for independent work in previous courses and in any earlier research involvement. Students doing theses will normally choose a topic and an adviser early in the second semester of their junior year. During the senior year, those students whose proposals have been approved will elect two courses and a Winter Study Project in addition to the minimum requirements for the major. At the end of the Winter Study Period, the department will decide, in consultation with each student, whether to admit that student to honors candidacy. Both a written thesis and an oral presentation to faculty and fellow students are required. The degree with honors will be awarded to those who meet these requirements with distinction. The degree with highest honors will be awarded to those who fulfill the requirements with unusually high distinction.

The department will be flexible with regard to the number and timing of courses devoted to thesis research within the general guidelines of two courses and a Winter Study Project over and above the minimum major requirements and the written and oral presentations, especially in cases of students with advanced standing and/or summer research experience. Students considering unusual requests are urged to consult with potential advisers or the department chair as early as possible.