Prosiectau Ffiseg ar gyfer myfyrwyr bl.3 a bl.4

Disgrifiad prosiect

Convection in stars

(supervisor: Youra Taroyan)

Nature of project: theory, theory

Available to students on full-time physics degree schemes or joint students.

Project description and methodology

When a layer of cold dense plasma is on top of hotter less dense layer, gravity pulls more strongly on the denser layer on top, so it falls while the hotter less dense plasma rises to take its place. This creates a circulating flow known as convection. Convection is a major energy transfer mechanism in stars. The aim of the project is to investigate the onset of convection, its relationship to internal gravity waves, the effects of magnetic fields, the role of convection in the formation of sunspots.

A successful project will develop beyond the above in one/some of the following directions:
Analytical investigation of the onset of convection using perturbation theory. The effect of a vertical magnetic field on convection will be analysed to understand the structure and the stability of sunspots.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: The stabilising/destabilising effect of a horizontal magnetic field on convection will be investigated.

Please speak to Youra Taroyan (yot) if you consider doing this project.

Initial literature for students:

  1. Priest, E. Solar Magnetohydrodynamics, Cambridge University Press, 2014
  2. Mullan, D. J. Physics of the Sun, CRC Press 2009
  3. Drazin, Introduction to Hydrodynamic Stability, Cambridge University Press, 2002

Novelty, degree of difficulty and amount of assistance required

The project is suitable for students with good analytical skills.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Overview of the main concepts end of October
Derivation of the criteria for the onset of convectionChristmas
Investigation of the magnetic effects mid-March
Overview and discussion of the resultsEaster