Module code: PHYM059

Module Overview

In this module, students will study the Universe from a dynamical perspective. They will study “collisional” stellar systems - from the dynamics of our Solar system and the supermassive black hole at the centre of our Galaxy, to the dynamical evolution of massive star clusters orbiting in the Milky Way. And, they will study “collisionless” systems, modelling the motion of stars and gas in galaxies. This will provide some of the key evidence for dark matter in the Universe. We will bring students up to a level where they will be at the forefront of modern research in this field.

Module provider

Mathematics & Physics

Module Leader

READ Justin (Maths & Phys)

Number of Credits: 15

ECTS Credits: 7.5

Framework: FHEQ Level 7

Module cap (Maximum number of students): N/A

Overall student workload

Independent Learning Hours: 96

Tutorial Hours: 11

Laboratory Hours: 11

Guided Learning: 10

Captured Content: 22

Module Availability

Semester 2

Prerequisites / Co-requisites

Introduction to Astronomy (year 2); Cosmology & Galaxy formation and Research Techniques in Astronomy are not required but would be advantageous.

Module content

-Introduction -

Astronomy as a unique science; observables, distance and time in astronomy; collisional versus collisionless stellar systems.


- Solving Gravity -

How to calculate the (classical) gravitational potential for systems of arbitrary complexity. We start with spherical or ‘oblate spheroidal’ systems in which Newton's theorems can be applied, before presenting general analytic solutions of the Poisson equation.


- Collisional systems -

We study the dynamics of collisional stellar systems, starting with our Solar system and the black hole at the centre of our Galaxy. We show that the Solar system is chaotic and discuss why it is in fact surprisingly stable. We calculate the mass of the dark object at the centre of the Galaxy and discuss similar data in other galaxies. Finally, we study the dynamics and thermodynamics of dense star clusters like the old Globular Clusters that orbit the Milky Way.


- Collisionless systems -

We discuss the dynamics of collisionless fluids like stars and dark matter in galaxies. We use the motion of these stars to derive the gravitational potential in galaxies and present key evidence for “dark matter” in the Universe. Finally, we discuss how dynamics can be used to unravel the past and predict the future of our Galaxy.


Assessment pattern

Assessment type Unit of assessment Weighting
Online Scheduled Summative Class Test ONLINE (OPEN BOOK) BI-WEEKLY TEST WITHIN 4HR WINDOW 10

Alternative Assessment


Assessment Strategy

Module aims

  • To provide students with a deep understanding of classic dynamics applied to the cosmos and what this can teach us about the formation of our Solar system, galaxies, and the Universe as a whole.

Learning outcomes

Attributes Developed
001 On successful completion of this module, students will be familiar with Lagrangian and Hamiltonian dynamics and will understand why the Solar System is chaotic. They will understand the difference between collisional and collisionless stellar systems and will be able to perform basic mass modelling of the black hole at the centre of our Galaxy, and stars in galaxies. Finally, they will understand the principle evidence for dark matter in the Universe and they will be able to compare and contrast ¿alternative gravity¿ models with ¿particle dark matter¿ models. The coursework assignment will further develop the students' programming and problem solving skills.

Attributes Developed

C - Cognitive/analytical

K - Subject knowledge

T - Transferable skills

P - Professional/Practical skills

Methods of Teaching / Learning

22 hours of lectures (2h/week; also available as captured content and written notes); 11 hours of tutorial classes (1h/week); 11 hours of computer lab for the coursework assignment (1h/week); 106 hours of independent learning.


Assessment will be through fortnightly online summative class tests (10%, with 24 hours to complete) and through a coursework assignment (90%). In the first part of the assignment, all students will write an orbit integrator to solve the orbit of a planet orbiting a star. They will learn about the difference between “symplectic” and “non-sympletic” integrators, and how to test and validate their numerical code. The students will then build on this to develop their own projects, exploring an aspect of the course that they found particularly interesting. This can be, for example, modelling the formation of "Kirkwood gaps" in the Solar System, or modelling the orbits of stars in our Galaxy and how they change due to the presence of dark matter. Since each project is unique and students interact weekly with the course leader to obtain feedback and advice on their project, anonymous marking for this coursework assignment will not be possible.

Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.

Reading list
Upon accessing the reading list, please search for the module using the module code: PHYM059

Programmes this module appears in

Programme Semester Classification Qualifying conditions
Physics MSc 2 Optional A weighted aggregate mark of 50% is required to pass the module
Physics with Nuclear Astrophysics MPhys 2 Optional A weighted aggregate mark of 50% is required to pass the module
Physics with Astronomy MPhys 2 Compulsory A weighted aggregate mark of 50% is required to pass the module
Physics with Quantum Technologies MPhys 2 Optional A weighted aggregate mark of 50% is required to pass the module
Physics MPhys 2 Optional A weighted aggregate mark of 50% is required to pass the module

Please note that the information detailed within this record is accurate at the time of publishing and may be subject to change. This record contains information for the most up to date version of the programme / module for the 2022/3 academic year.