Overview

I’m an astrophysicist who studies the wispy but explosive atmosphere of our star, the Sun. I use, operate, and help design space missions that tell us about the Sun we can’t see from inside our own, protective atmosphere.

I look at the Sun in ultraviolet light, where it’s covered in rope-like filaments, tenuous bright magnetically-shaped loops and puzzlingly hot ionised gas (plasma).

The techniques I use split the Sun’s UV light into its individual colours to tell us what it’s made of, how it moves and what the conditions are that produce violent explosions like flares and coronal mass ejections.

A big part of what I do uses data from the Hinode satellite, in particular its EUV Imaging Spectrometer. In addition, I work with people and data from other space missions (SoHO, Solar Dynamics Observatory in particular), and with people who do the very hard work of trying to simulate or model the physics that takes place in various situations on the Sun.

Filaments on the Sun

I look at the Sun in ultraviolet light, where it’s covered in rope-like filaments, tenuous bright magnetically-shaped loops and puzzlingly hot ionised gas (plasma). Filaments are really fascinating structures hovering in the corona, at the interface between low and high states of ionisation, density, plasma β and temperature. This really begs us to understand not only their structure, but also their creation and often explosive destruction, which can lead to ejections of material that large parts of the solar system when they happen.

Active regions

Solar active regions, areas of intense and often complex magnetic fields on the Sun, play host to some filaments. But they are also interesting for another reason: in the unusually hot solar corona, these are the hottest sites of all, and they can release energy suddenly and violently, as well as continuously, from the reordering of these magnetic fields. This ongoing magnetic furnace can throw our usual easy rules-of-thumb about plasma behaviour out the window. Understanding how plasma is heated, and whether it behaves like a normal Maxwellian “gas”, or has a long-lasting population of high-energy particles, is something we can probe through UV and X-ray spectroscopy (something Solar Orbiter will really help us to do).