Q. Academic Requirements
To be admitted as a Ph.D. student at the Institute of Astronomy, you need a good UK 2.1 four-year undergraduate honours degree (or five years if from a Scottish University). If you're unsure about your overseas degree's UK equivalent, contact the IoA Admissions Office.
In the UK, students usually complete a four-year undergraduate degree leading to an integrated master's degree. In many other countries, like Europe, India, and the USA, a three- or four-year undergraduate degree followed by a two-year master's degree is required. Note that a four-year bachelor's degree from Australia or New Zealand is not considered equivalent to a UK integrated master's degree; a separate master's degree is needed.
When assessing applications, the University looks at your undergraduate academic record, relevant research experience, and the availability of a project/supervisor in your chosen area. For students on a North American GPA system (out of 4.0), a GPA of at least 3.8 is typically needed.
The Ph.D. program is best for students with an undergraduate degree in astrophysics or theoretical physics. If your background is in another field, like mathematics or computer science, you usually need a master's degree with significant astrophysics or physics content. For those interested in theoretical research, the one-year MASt in Mathematics or MASt in Astrophysics can provide the necessary background. Many students from these courses are later admitted to the PhD program at the Institute of Astronomy.
Q. My academic training is not in astrophysics, can I apply to become a PhD student in astrophysics at the IoA?
If your academic background isn’t in astrophysics, you can still apply for a PhD at the Institute of Astronomy (IoA), but there are important things to consider. The PhD programme is a focused, three-year research course, and it assumes you already have a strong foundation in astrophysics or physics, typically from undergraduate through to master’s level. There isn’t enough time during the PhD to build this background from scratch while also completing the required research.
If your training is in another field—like engineering, computing, or pure mathematics—you’ll likely need to complete a master’s degree that includes significant astrophysics or physics content before applying. For those interested in theoretical areas, the one-year MASt in Mathematics or MASt in Astrophysics at Cambridge are good options. Several students each year who complete these courses go on to start a PhD at the IoA.
If you're serious about pursuing a PhD in astrophysics but don’t yet have the necessary background, a UK-style three-year PhD may not be the best fit. Instead, consider a five-year PhD in the USA, which includes two years of coursework, or a two-year astrophysics master’s programme in Europe—such as those offered by the universities of Manchester, Sussex, or Leiden.
Q. My undergraduate degree is from the USA, what is the academic requirement for entry to the PhD course?
If you earned your undergraduate degree in the USA and are interested in applying for a PhD at the Institute of Astronomy (IoA), it’s important to understand how the UK and US systems differ. In the UK, students usually begin a PhD after completing a four-year degree focused almost entirely on physics, astrophysics, and mathematics, they start research immediately and finish the PhD in just three years.
In contrast, US PhD programmes typically include two years of coursework before research begins. This means that students coming straight from a US undergraduate programme often don’t have the depth in physics and maths needed to start a UK PhD right away. As a result, it’s rare for students from the US to be admitted directly after their undergraduate studies—especially for research areas like cosmology or the cosmic microwave background.
However, if you're interested in observational or data-focused projects, admission may be possible. To be considered, you should have completed a four-year US degree with a strong focus on physics and maths, including some advanced-level courses. A GPA of at least 3.8 (on a system with a maximum of 4.0) is expected, and most successful applicants have a GPA of 3.9 or higher. You should also have completed at least one research internship or project in astrophysics.
Q. My undergraduate degree is not from the UK, what is the academic requirement for entry to the PhD course?
While the University of Cambridge requires the equivalent of a good 2.1 in a four-year integrated Master’s degree, most international applicants are expected to have the equivalent of a strong First Class degree.
Please visit the Graduate Admissions webpage for further information regarding International Qualifications.
Q. Do I need to identify a supervisor before I apply?
Please see our 'How to Apply' and 'Funding for PhD Students' sections.
Q. What happens if I am called for interview and a visit?
If you're a Home-fee applicant in the UK, you're encouraged to spend at least half a day visiting the Institute. During your visit, staff will be available to speak with you individually about potential PhD topics, and you'll also have the chance to meet current postgraduate students.
Your interview will last about 30 minutes and will be conducted by three members of the Postgraduate Admissions Committee. They’ll ask about your undergraduate studies, master’s research project, and research interests. You’ll also have time to ask your own questions.
The Institute will cover reasonable travel costs for your visit.
Overseas applicants will usually be interviewed by Zoom in January.
Q. When will the results of applications for scholarships be available?
Final decisions for U.S. Gates applicants will usually be announced by the end of January 2026.
Gates Cambridge, University and Cambridge Trust Scholarships will be announced from late March 2026.
STFC Studentships will be awarded end of February/early March.
Q. How much does it cost to undertake a PhD?
Please refer to the Finance section PhD in Astronomy | Postgraduate Study
Q. Can I undertake a PhD as a part-time student?
The University now allows part-time PhD study in principle across all subjects. However, in astrophysics, part-time study is often challenging due to the fast-paced nature of research. Many projects rely on short-term access to data, supercomputers, and funding, which doesn’t align well with the five- to seven-year timeline of a part-time PhD. As a result, most research projects at the Institute of Astronomy aren’t naturally suited to part-time study and would need to be specially designed.
If you're considering a part-time PhD, you must first contact potential supervisors to see if a suitable project can be developed. In some cases, it may not be possible to create a viable part-time project.
If you’ll need a visa to study part-time, it’s essential to read the guidance on the International Students website before applying.
Q. English is not my first language, do I need to take an English Language test before I apply?
If you receive a conditional offer and haven’t yet met the University’s English language requirements, you’ll need to pass an approved test at the required level. Test results are only valid for two years. You can find the list of accepted tests and the required scores for this course https://www.postgraduate.study.cam.ac.uk/apply/before/english-language-requirements