Proposals for Bachelor and Master's Thesis projects

The main areas of my research, and hence of the projects I'll supervise, are numerical astrophysics and simulations of astrophysical magneto-hydrodynamics (MHD). Here are a couple of examples of ready-to-launch projects:

A magnetic star-in-a-box: Betelgeuse and super-giants

So far models of magnetic fields and dynamos in stars have been very crude. For example people often model just a small section of a star, and look at the behavior of magnetic fields in an idealized manner. Especially for stars that have huge convection cells at the surface, the magnetic field may also be more global than can be rendered in an idealized simulation. First steps have already been taken to model cool giant stars (such as the red-giant "Betelgeuse") in a holistic way, as a "star-in-a-box": In this project the Master's student makes model(s) of convective stars including the magnetic field.
Material containing an initial simplified study, and a well-documented (ready to run) computer code are available. The project will with great likelihood result in a publication in a peer-reviewed international journal.

Material: first ideas, computer code, see also Aktuel Astronomi (Vinter 2003), p.36-39, for an introduction in Danish.

The Jovian Dynamo

Like the Sun, the stars and the Earth, Jupiter also generates it's own magnetic field in an enigmatic dynamo process: It is this dynamo that is responsible for the magnetic field that interacts with the magnetic field in the solar wind, thereby creating the auroral displays (left picture above) similar to the ones we see on Earth. But... Is Jupiter's dynamo similar to Earth's (the geodynamo) or to the solar and stellar dynamos? A possible Master's Thesis project could study this so-called Jovian dynamo by means of numerical simulation to an extend never attempted before: The whole planet can be modeled in a large-scale numerical simulation, making it possible to study the dynamics of the field and flows on a global scale.

Material: computer code

Activity on cool red dwarf stars

Many cool late-type dwarf stars (i.e. stars like the Sun, or cooler) are thought to have magnetic coronae e.g. because of their observed X-ray activity. In some cases the inferred magnetic fields have filling factors of 70% of the surface, which may be compared to the 1% filling factor of the Sun at solar maximum. In addition some M-type (red) dwarf stars are rotating faster than the Sun and the magnetic field strength on their surfaces are higher than on the Sun: Do these stars have dynamos that are different from the solar dynamo? Do they have solar-like coronae with magnetic loops, like the Sun, or does the observed activity have a different explanation? This project could aim at modeling an M-dwarf corona, in a way similar to the recent successful models of the solar corona (and coronal heating), by one of the Ph.D. students of our group (by using the same computer code).

Material: setup for the Sun (by Boris Gudiksen), M-dwarf dynamo?

The solar dynamo: Observation and analysis of solar magnetic fields

Use the publically available data from the SST to unravel the solar dynamo; what are the structure of emerging active regions? Do magnetic flux ropes really exist; do they look anything like those we assume in our numerical computer simulations?

Material: The Swedish Solar Telescope, Dorch, S.B.F. 1998, Ph.D. Thesis

A number of additional masters projects and colloquia subjects are possible, in connection with on-going  projects in the Numerical Astrophysics group. For more detailed information, contact one of us for a discussion.


May 2012 dorch@astro.ku.dk