University of Exeter funding: Modelling the formation of planetar

Modelling the formation of planetary building blocks, Astrophysics - PhD (Funded) Ref: 3839

About the award


Lead Supervisor

Dr. Sebastiaan Krijt, Department of Physics and Astronomy, University of Exeter

Additional Supervisor:

Professor Matthew Bate, Department of Physics and Astronomy, University of Exeter


The University of Exeter’s College of Engineering, Mathematics and Physical Sciences is inviting applications for a fully-funded PhD studentship to commence in September 2020 or as soon as possible thereafter.  For eligible students the studentship will cover UK/EU/International tuition fees plus an annual tax-free stipend of at least £15,009 for 3.5 years full-time, or pro rata for part-time study.  The student would be based in the Astrophysics Group in the College of Engineering, Mathematics and Physical Sciences at the Streatham Campus in Exeter.

Location: Department of Astonomy and Physics, University of Exeter, Streatham Campus, Exeter, Devon, UK. 

Project Description:

The last two decades have taught us that planetary systems are widespread in the galaxy. Moving beyond the detection of exoplanets, an important component of characterising these worlds will be understanding their formation history: Which processes determined a planet’s final size, mass, orbit, and composition? The modern paradigm dictates that the first step of planet formation is the coagulation of small, microscopic dust particles into pebbles, which then come together to form “planetesimals”: gravitationally bound planetary building blocks. The details of these early stages however are enigmatic, and it is not clear where and when in the disc planetesimals can be created, or where the pebbles that form them originated from.

The theme of this PhD project is simulating the beginnings of planet formation inside gas-rich protoplanetary discs. The student will (further) develop novel numerical techniques to model dust coagulation, the chemical evolution of protoplanetary disc materials, and the creation of planetesimals. The goal will be to predict the chemical compositions of the forming planetesimals and understand how these reflect the physical and chemical conditions in the protoplanetary nebula. Where possible, model predictions will be compared to observational constraints such as ALMA observations of gas and dust in young protoplanetary discs, or results from in-situ measurements of left-over planetesimals in our own solar system (e.g., comets, asteroids).

While focused on using and developing numerical simulations, this project is highly interdisciplinary in nature, and the successful applicant will become familiar with and employ concepts from the astrochemistry, observational astronomy, laboratory astrophysics, and theoretical planet formation communities. Depending on the interests of the applicant, international collaborations across these disciplines may be pursued.


ALMA image of the protoplanetary disc around the young star HL Tauri. The disc is approximately the size of our Solar System and at these wavelengths ALMA is observing the thermal emission of cold, millimetre-size dust particles. Credit: ALMA (ESO/NAOJ/NRAO). (Taken from:


Fig 2 A fractal dust aggregate of about 03 mm in diameter that was formed in a computer simulation

A fractal dust aggregate of about 0.3 mm in diameter that was formed in a computer simulation. The aerodynamical, optical, and mechanical properties of such aggregates depend on their growth history and composition. Credit: Seizinger, Krijt & Kley (2013, A&A, 513, A45).  (Full paper:

Entry requirements

Applicants for this studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology. 

If English is not your first language you will need to have achieved at least 6.0 in IELTS and no less than 6.0 in any section by the start of the project.  Alternative tests may be acceptable (see

How to apply

In the application process you will be asked to upload several documents:

  • CV
  • Letter of application (outlining your academic interests, prior research experience and reasons for wishing to undertake the project).
  • Transcript(s) giving full details of subjects studied and grades/marks obtained (this should be an interim transcript if you are still studying)
  • Two references from referees familiar with your academic work. Please ask your referees to email the reference direct to quoting the studentship reference number, or upload them with your application.
  • If you are not a national of a majority English-speaking country you will need to submit evidence of your proficiency in English.

The closing date for applications is midnight on Monday 27 January 2020

If you have any general enquiries about the application process please email or phone +44 (0)1392 722730 or +44 (0)1392 725150.  Project-specific queries should be directed to Dr Sebastiaan Krijt (


Application deadline:27th January 2020
Duration of award:per year
Contact: STEMM PGR Admissions