Postgraduate research project

Starfire: simulating thermonuclear ignition on neutron stars

Funding
Competition funded View fees and funding
Type of degree
Doctor of Philosophy
Entry requirements
2:1 honours degree View full entry requirements
Faculty graduate school
Faculty of Engineering and Physical Sciences
Closing date

About the project

What happens when nuclear fire races across the surface of a neutron star? This project uses numerical simulations to study how thermonuclear X-ray bursts ignite and spread, linking computational models with observations. You will develop transferable coding skills while exploring extreme astrophysics, with applications extending to stellar explosions and exoplanet atmospheres.

Type I X-ray bursts—also known as thermonuclear bursts—occur on the surfaces of neutron stars in low-mass X-ray binary systems. As gas from a companion star accretes onto the neutron star, it spreads across the surface and forms a layer of fresh material. Under the star’s immense gravity, this layer becomes compressed and heated until it reaches the critical temperature and density required for thermonuclear ignition.

At that point, nuclear fusion of hydrogen begins, rapidly converting hydrogen into helium and later to heavier elements. The resulting runaway nuclear burning releases an enormous amount of energy in the form of X-rays—an a burst  lasting only seconds to minutes, yet radiating more energy than the Sun emits in a week. These bursts provide a unique observational window into the extreme physical conditions found on neutron star surfaces.

In this project, you will develop and run numerical simulations to model how the burning front spreads across the neutron star once ignition occurs. The results will be compared with observational data and theoretical predictions to refine our understanding of thermonuclear processes in compact stars.

Beyond neutron stars, you will also explore how the computational tools and methods developed here can be applied to other astrophysical and planetary contexts—such as flame propagation in other stellar environments and atmospheric dynamics on exoplanets.

You will join the High-Energy Astrophysics Group at the University of Southampton and collaborate with leading researchers worldwide. We are looking for a candidate who enjoys programming and has strong coding skills, with enthusiasm for using computational methods to tackle challenging astrophysical problems.

The School of Physics and Astronomy is committed to promoting equality, diversity inclusivity as demonstrated by our Athena SWAN award. We welcome all applicants regardless of their gender, ethnicity, disability, sexual orientation or age, and will give full consideration to applicants seeking flexible working patterns and those who have taken a career break. 

The University has a generous maternity policy, onsite childcare facilities, and offers a range of benefits to help ensure employees’ well-being and work-life balance. The University of Southampton is committed to sustainability and has been awarded the Platinum EcoAward.