A department entered after arrival
Princeton says students apply to the University, not to departments, and A.B. students choose a major in the spring of the sophomore year.
Undergraduate · Princeton
Princeton Astrophysical Sciences: physics-heavy, thesis-led, chosen after arrival
Princeton admits students to the University, not to a department, and Astrophysical Sciences is one of the A.B. majors they can choose once enrolled. The Undergraduate Announcement for 2026-2027 describes a department that covers planets to cosmology, expects advanced physics and mathematics, and builds the degree around junior and senior research. This guide explains that structure as a documented major for current students. It does not present it as a confirmed requirement for 2028 entrants, and makes no claim of a separate application to the major.
Official information · read 1 November 2026, no entry-year label
What Princeton says about Princeton Astrophysical Sciences
Taken from the Astrophysical Sciences entry in the Princeton Undergraduate Announcement 2026-2027, Princeton Admission's Academics, Standardized Testing and International Students pages, read on 1 November 2026. The pages carry no entry-year label, so for a 2028-entry application every statement below is evidence for the previous cycle and may change; check Princeton's pages for the 2028-entry details.
Mathematics, physics and AST 204 first
The Announcement lists MAT 103, 104, 201 and 202 or equivalent, PHY 103/105, 104/106 and 207, and AST 204 as prerequisites.
Eight upper-level courses
At least four astrophysics courses at the 300-400 level, at least three physics courses and one more STEM course, plus the independent research courses.
No tracks
The department says there are no tracks; students plan courses and research projects with the director of undergraduate studies.
A senior thesis or independent project
Princeton says every senior writes a thesis or, in some engineering departments, undertakes a substantial independent project.
The SAT or ACT is required
Princeton says fall 2028 first-year applicants need to submit either SAT or ACT scores.
Official sources
- Princeton Admission: Academicsadmission.princeton.edu
- Princeton Undergraduate Announcement 2026-2027: Astrophysical Sciencesua.princeton.edu
- Princeton Admission: Standardized Testingadmission.princeton.edu
Read on 1 November 2026 on the Astrophysical Sciences entry in the Princeton Undergraduate Announcement 2026-2027, Princeton Admission's Academics, Standardized Testing and International Students pages, which describes 2027 entry. The pages carry no entry-year label. Princeton's department website, the full course descriptions, deadlines and financial aid were not read and are not stated.
The department
What the Announcement says the major requires
The Announcement describes a major for students who plan graduate study in astrophysics and also for those aiming at science education, science policy, space exploration, data science, law, medicine or finance. Students take the listed mathematics and physics prerequisites and AST 204, then at least four astrophysics courses at the 300-400 level, at least three physics courses and one more STEM course. Independent work is part of every path: at least one junior independent research project (AST 398), then the year-long senior thesis (AST 498-499), the oral defence and a brief oral examination. This guide did not read the departmental website, the course descriptions or the faculty research pages.
Is it the right department?
Astrophysical Sciences beside other science majors
Princeton describes these separately, so the choice is made after admission. Avandy's comparison is general.
Astrophysical Sciences fits if
you want astronomy and cosmology as the subject and are comfortable with an advanced physics and mathematics base.
Mathematics fits if
the mathematics itself is the interest. Avandy's Princeton Mathematics guide covers that major.
A.B. versus B.S.E. fits as a separate question
Princeton describes the A.B. and the engineering B.S.E. separately; Avandy's Princeton A.B. and B.S.E. guide explains the choice.
Admission and testing
A Princeton application and the SAT or ACT
Princeton asks for an academic record that includes internal grades and marks from external exams such as A levels or the IB, with predicted or achieved results sent as they become available. It says first-year applicants for fall 2028 will need to submit either SAT or ACT scores. The department is chosen after enrolment, not applied for separately. This guide states no score.
A decision framework
Three questions before you commit
This is Avandy's own framework, not Princeton's.
Are you ready for physics and mathematics through multivariable calculus and linear algebra?
The listed prerequisites include MAT 201 and 202 or equivalent.
Does a year of independent research appeal?
Every major completes junior independent work and a senior thesis.
Can you plan the SAT or ACT with your A levels or IB?
Princeton says fall 2028 first-year applicants need to submit one of them.
Planning for 2028 entry
Planning for 2028 entry: what carries over and what is awaiting publication
Princeton's pages carry no entry-year label, so nothing on them is confirmed for 2028 entry. Use them to understand the structure of the application, then check Princeton's own pages for the 2028-entry details.
The Princeton Undergraduate Announcement 2026-2027 entry for the major, read on 1 November 2026: a documented major structure for current students, not a confirmed requirement for students entering in 2028
Princeton's University-wide admission pages for fall 2028, which set the testing and application rules this guide reports
Anything specific to the major requirements that will apply to 2028 entrants: not published
This guide has not read it. Check the Announcement edition that applies when you enrol.
What to do now
Read the Undergraduate Announcement entry for the major and plan the SAT or ACT alongside your A levels or IB.
Support
Independent support with planning your own application
Avandy provides independent academic and admissions support. It is not affiliated with Princeton University or any of its colleges or departments. Preparation sits within the Avandy Trinity Advisory Model: a Strategic Admissions Consultant, a PhD-level Academic Mentor and a Subject-specific Tutor, working to the actual requirements of each course. Support here is limited to understanding the requirements and planning the applicant's own work; Avandy does not write or edit essays, does not submit any materials and has no partnership with Princeton University. No outcome is promised.
Questions
Questions applicants ask
Can I apply directly to Princeton Astrophysical Sciences?
No. Princeton says students apply to the University, not to individual departments, programs or schools.
Does Astrophysical Sciences have tracks?
No. The Announcement says there are no tracks, and that individual plans can be made with the director of undergraduate studies.
Is there a thesis?
Yes. Students complete AST 498-499, a year-long senior thesis, and give an oral defence.
Which mathematics is listed as a prerequisite?
MAT 103, 104, 201 and 202 or equivalent, in the Announcement's wording.
Do I need the SAT or ACT?
Princeton says first-year applicants seeking to enrol in fall 2028 will need to submit either SAT or ACT scores.
Do A levels and the IB count?
Princeton asks for marks from external exams such as British A levels or the International Baccalaureate, with predicted or achieved results as they become available.
Are these the rules for 2028 entry?
No. They are Princeton's wording with no entry-year label. Check Princeton's pages again when Princeton publishes its 2028-entry requirements.
Students and families
Talk to us about Princeton Astrophysical Sciences
Tell us about the student's curriculum, their mathematics and physics, how much they want research in the major and their SAT or ACT plan, the universities on the list, and the intended year of entry. A senior adviser will review the academic profile before recommending how to prepare.