Department of Astrophysical Sciences



  • Michael A. Strauss

Associate Chair

  • Eve C. Ostriker

Director of Undergraduate Studies

  • Neta A. Bahcall

Director of Graduate Studies

  • Joshua N. Winn


  • Neta A. Bahcall
  • Gáspár Áron Bakos
  • Amitava Bhattacharjee
  • Adam S. Burrows
  • Christopher F. Chyba
  • Steven C. Cowley
  • Bruce T. Draine
  • Jo Dunkley
  • Nathaniel J. Fisch
  • Robert J. Goldston
  • John J. Goodman
  • Jenny E. Greene
  • Hantao Ji
  • David J. McComas
  • Eve C. Ostriker
  • Felix I. Parra Diaz
  • Eliot Quataert
  • Anatoly Spitkovsky
  • Michael A. Strauss
  • Romain Teyssier
  • Joshua N. Winn

Associate Professor

  • Matthew W. Kunz

Assistant Professor

  • Peter M. Melchior

Associated Faculty

  • Mariangela Lisanti, Physics
  • Lyman A. Page, Physics
  • Frans Pretorius, Physics
  • Suzanne T. Staggs, Physics
  • Paul J. Steinhardt, Physics
  • Robert J. Vanderbei, Oper Res and Financial Eng

Lecturer with Rank of Professor

  • Samuel A. Cohen
  • Ilya Y. Dodin
  • Gregory W. Hammett
  • Richard P. Majeski
  • Hong Qin
  • Allan H. Reiman
  • William M. Tang


  • Philip C. Efthimion
  • William R. Fox
  • Jong-Kyu Park
  • Yevgeny Raitses

Visiting Lecturer with Rank of Professor

  • Matias Zaldarriaga

Visiting Lecturer

  • Michael D. Lemonick
For a full list of faculty members and fellows please visit the department or program website.

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 its 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 103, 104, 201, 202 or equivalent, and Physics 103/105, 104/106, 207; and Astrophysical Sciences 204.

Early Concentration

Students interested in early concentration in astrophysics should contact the director of undergraduate studies.

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 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 their adviser, can range from areas such as cosmology and the early universe, to galaxy formation, to 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 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 a 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 QRSN

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, A. Spitkovsky

AST 204 Topics in Modern Astronomy Spring QRSN

The solar system and planets around other stars; the structure and evolution of stars; supernovae, neutron stars, and black holes; gravitational waves; the formation and structure of galaxies; cosmology, dark matter, dark energy, and the history of the entire universe. Prerequisites: PHY 103 or 105 and MAT 103 or 104 or equivalent. Compared to AST 203, this course employs more mathematics and physics. Intended for quantitatively-oriented students. Instructed by: J. Winn

AST 205 Planets in the Universe Fall QRSN

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 SEN 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 255 Life in the Universe (also
CHM 255
GEO 255
) Not offered this year QRSN

This course introduces students to a new field, Astrobiology, where scientists trained in biology, chemistry, astrophysics and geology combine their skills to investigate life's origins and to seek extraterrestrial life. Topics include: the origin of life on earth, the prospects of life on Mars, Europa, Titan, Enceladues and extra-solar planets, as well as the cosmological setting for life and the prospects for SETI. AST 255 is the core course for the planets and life certificate. Instructed by: C. Chyba

AST 301 General Relativity (also
PHY 321
) Not offered this year SEN

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 Deciphering the Universe: Research Methods in Astrophysics Fall QRSN

How do we observe and model the universe? We discuss the wide range of observational tools available to the modern astronomer: from space-based gamma-ray telescopes, to globe-spanning radio interferometers, to optical telescopes and particle detectors. We review basic statistics, introduce techniques used to interpret modern data sets containing millions of galaxies and stars, and describe numerical methods used to model these data. The course is problem-set-based and focused on tools needed for independent research in astrophysics. PHY103/104 or 105/106, and MAT103/104 required. AST204 and programming experience are helpful but not required. Instructed by: P. Melchior, M. Kunz

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

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
) Not offered this year

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
) Spring SEN

Stars form from the interstellar medium (ISM), and the nuclear fusion that powers stars is also the main energy source in the ISM. This course discusses the structure and evolution of the ISM and stars. Topics include: physical properties and methods for studying ionized, atomic, and molecular gas in the ISM; dynamics of magnetized gas flows and turbulence; gravitational collapse and star formation; structure of stellar interiors; radiation transport; production of energy by nucleosynthesis; stellar evolution and end states; effects of stars on interstellar environment. Prerequisites: MAT 201, 202; PHY 208, 301 or permission of instructor. Instructed by: E. Ostriker