Department of Astrophysical Sciences


  • Chair

    • Michael A. Strauss
  • Director of Undergraduate Studies

    • Neta A. Bahcall
  • Director of Graduate Studies

    • Anatoly Spitkovsky
    • Josh Winn (acting DGS, AY 2019-20)



  • Professor

    • Neta A. Bahcall
    • Gáspár Áron Bakos
    • Amitava Bhattacharjee
    • Adam S. Burrows
    • Christopher F. Chyba
    • Bruce T. Draine
    • Jo Dunkley
    • Nathaniel J. Fisch
    • Robert J. Goldston
    • Jeremy J. Goodman
    • Jenny E. Greene
    • Hantao Ji
    • Eve Charis Ostriker
    • Stewart C. Prager
    • Anatoly Spitkovsky
    • Michael A. Strauss
    • Edwin L. Turner
    • Joshua N. Winn






  • Assistant Professor

    • Matthew W. Kunz
    • Peter M. Melchior
  • Visiting Lecturer with Rank of Professor

    • Matias Zaldarriaga

  • Visiting Lecturer

    • Michael D. Lemonick

Program Information

Information and Departmental Plan of Study

The Department of Astrophysical Sciences offers an outstanding program for astrophysics majors with the flexibility to accommodate students with a broad range of interests. Many of our majors plan to continue in graduate school in astrophysics. For students with career goals in other areas such as science education, science policy, space exploration, as well as law, medicine, finance, and teaching, we offer a flexible choice of courses and research projects. The department covers all major fields in astrophysics -- from planets, to black holes, stars, galaxies, quasars, dark matter, dark energy, and the evolution of the universe from the Big Bang to today. The relatively small size of the department provides an informal, flexible, and friendly setting for students. The department is known for providing strong and supportive mentorship to all students, for cutting-edge independent research done by students for their JPs and theses, as well as for the warm and amiable atmosphere. Full accessibility to all faculty members and to the excellent departmental facilities, including our on-campus and remote telescopes and sophisticated computer system, is provided.


Mathematics 201, 202 or equivalent, and Physics 205; Astrophysical Sciences 204 is strongly recommended.

Early Concentration

Students interested in early concentration in astrophysics should contact the departmental representative.

Program of Study

Every student majoring in astrophysical sciences will acquire the necessary training in astrophysics by taking at least three astrophysics courses at the 300 or 400 level. In addition to these courses, departmental students will take courses in the Department of Physics that provide basic training in mechanics, quantum mechanics, electromagnetic theory, and other relevant topics.

Independent Work

Junior Year. In addition to the course work carried out during the junior year, each student carries out two junior independent research projects, one each semester. Each project is on a research topic of current interest, carried out under close supervision of a faculty adviser who is doing research in this area. The student will complete each term's independent work by submitting a written paper. The research projects can involve data analysis using astronomical data from our telescopes, including data from the Sloan Digital Sky Survey -- a unique three-dimensional map of the universe -- and the Hyper Suprime-Cam Survey with the Subaru telescope, as well as data from other national and international facilities such as the Hubble Space Telescope. Similarly, theoretical and computational projects in astrophysics are available. The topics, to be selected jointly by the student and his/her adviser, can range from areas such as cosmology and the early universe, to galaxy formation, large-scale structure of the universe, quasars, black holes, stars, extra-solar planets, high-energy astrophysics, and plasma astrophysics. Interdisciplinary projects, including astronomy and education, science policy, planetary science, astrobiology, space science exploration, and more are possible.

Senior Year. In the senior year, in addition to course work, students carry out an extensive research project with a faculty adviser for their senior thesis. The thesis is completed by submitting the final written paper summarizing the work. There is a wide range of observational and theoretical topics available, including interdisciplinary projects as discussed above. The senior thesis work is frequently published as part of a scientific paper in an astrophysical journal. After the thesis has been completed and read by the adviser and an additional faculty member, the student presents an oral summary of the work, followed by an oral defense of the thesis.

Senior Departmental Examination

The thesis work and the oral defense, combined with a brief oral examination on general topics in astrophysics, compose the senior departmental examination.

Preparation for Graduate Study

The undergraduate program in the department provides an excellent preparation for graduate study in astrophysics, with concentrators frequently accepted at the top graduate schools in the country.

Additional Courses: See Course Offerings, especially for courses offered on a one-time-only basis.


AST 203 The Universe Spring QR

This specially designed course targets the frontier of modern astrophysics. Subjects include the planets of our solar system; the birth, life, and death of stars; the search for extrasolar planets and extraterrestrial life; the zoo of galaxies from dwarfs to giants, from starbursts to quasars; dark matter and the large-scale structure of the universe; Einstein's special and general theory of relativity, black holes, neutron stars, and big bang cosmology. This course is designed for the non-science major and has no prerequisites past high school algebra and geometry. High school physics would be useful. Instructed by: M. Strauss, C. Chyba, J. Dunkley

AST 204 Topics in Modern Astronomy Spring STN

The birth and evolution of the stars; supernovae, neutron stars, and black holes; the formation, structure, and evolution of galaxies; cosmology, dark matter, dark energy, and the evolution of the universe from the Big Bang to today. Prerequisites: PHY 103 or 105 and MAT 103 or 104 or equivalent. Intended for students in the sciences. Instructed by: J. Winn

AST 205 Planets in the Universe Fall STN

This is an introductory course in astronomy focusing on planets in our Solar System, and around other stars (exoplanets). The course starts with reviewing the formation, evolution and characterization of the Solar system. Following an introduction to stars, the course will then discuss the exciting new field of exoplanets; discovery methods, basic properties, earth-like planets, and extraterrestrial life. Core values of the course are quantitative analysis and hands-on experience, including telescopic observations. This STN course is designed for the non-science major and has no prerequisites past high school algebra and geometry. Instructed by: G. Bakos

AST 207 A Guided Tour of the Solar System (See GEO 207)

AST 255A Life in the Universe (See GEO 255A)

AST 255B Life in the Universe (See GEO 255B)

AST 301 General Relativity (also
PHY 321
) Fall STN

This is an introductory course in general relativity for undergraduates. Topics include the early universe, black holes, cosmic strings, worm holes, and time travel. Designed for science and engineering majors. Two 90-minute lectures. Prerequisites: MAT 201 and 202, OR MAT 203 and 204. Also PHY 205 or 207. PHY 304 is recommended. Instructed by: J. Goodman

AST 303 Modeling and Observing the Universe: Research Methods in Astrophysics Not offered this year

Introduces students to the techniques that astrophysicists use to model and observe the universe. The course will prepare students in research methods that will be used in their independent work in astrophysics. The techniques covered will be useful for students concentrating in any of the natural sciences. Topics include methods of observational astronomy, instruments and telescopes, statistical modeling of data, and numerical techniques. Two 90-minute lectures. Prerequisites: PHY 103-104, or PHY 105-106, and MAT 103-104, or permission of instructor. Instructed by: M. Strauss, J. Greene

AST 309 The Science of Fission and Fusion Energy (also
MAE 309
PHY 309
ENE 309
) Spring

We develop the scientific ideas behind fission and fusion energy. For fission we move from elementary nuclear physics to calculations of chain reactions, understanding how both reactors and nuclear weapons work. We examine safety and waste concerns, as well as nuclear proliferation. We look at new reactor concepts. For fusion we address the physics of confining hot, ionized gases, called plasmas. We address the control of large-scale instabilities and small-scale turbulence. We examine progress and prospects, as well as challenges, for the development of economically attractive fusion power. Instructed by: R. Goldston

AST 374 Planetary Systems: Their Diversity and Evolution (See GEO 374)

AST 401 Cosmology (also
PHY 401
) Spring

Topics include the properties and nature of galaxies, quasars, clusters, superclusters, the large-scale structure of the universe, dark matter, dark energy, the formation and evolution of galaxies and other structures, microwave background radiation, and the evolution of the universe from the Big Bang to today. Two 90-minute lectures. Prerequisites: MAT 201, 202; PHY 207, 208. Designed for science and engineering majors. Instructed by: N. Bahcall

AST 403 Stars and Star Formation (also
PHY 402
) Not offered this year

Stars form by the gravitational collapse of interstellar gas clouds, and as they evolve, stars return some of their gas to the interstellar medium; altering its physical state and chemical composition. This course discusses the properties and evolution of the gaseous and stellar components of a galaxy; the physics of the diffuse and dense interstellar medium, the theory and observations of star formation; stellar structure; energy production and nucleosynthesis; stellar evolution; and stellar end states. Two 90-minute lectures. Prerequisites: MAT 202; PHY 207, 208. Instructed by: B. Draine, A. Burrows