Dying stars & the chemical history of the Universe

My main area of research is in the death of stars like the Sun. These stars spend their lives making heavier elements. They die by throwing off their outer atmospheres, making these new elements into stardust. This stardust enriches the Universe with the necessary ingredients to build new stars, rocky planets and life. I look at how this process happens and how it has changed over the history of the Universe.

To detect the gas and dust the comes off these stars, we need some of the most sensitive telescopes on the planet. I use data from a wide range of telescopes, including the Very Large Telescope and Atacama Large Millimetre Telescopes in Chile and the Spitzer Space Telescope.

Most of my research uses in clusters of stars or in nearby dwarf galaxies. The simple groups of stars have well-known properties: we have a good idea what the stars are made of, how old they are, and how big they are. This makes it easier to see how the death of stars changes with these properties.

A globular cluster
Omega Centauri, as seen by Spitzer

An exoplanet
Credit: Mark Garlick

Transiting Extrasolar Planets

My side interest is in extrasolar planets. I don't get paid for this, so it has to take second priority!

Extra-solar planets are planets that orbit their parent stars much like the Earth does the Sun. If the orbits of these planets happen to be aligned so they pass in front of their stars, they block out a little of that star's light. By measuring how the brightness varies over time, we can determine how fast it goes around its star and how big the planet is. By splitting the star's light into a spectrum, we can estimate how heavy both the star and the planet are.

I have used Keele's 24-inch telescope to follow up possible planets found by the WASP collaboration, and am involved in the Euclid Space Telescope working group on planets.

Odds & sods

I'm also interested in almost everything else astronomical, whether that's the breakup of comets, novae outbursts, supernovae, or just taking pretty pictures. Outside astronomy, I am active in the genetic anthropology community.
A comet
73P/Schwassmann-Wachmann 3
Credit: NASA, ESA, H. Weaver (JHU/APL), M. Mutchler & Z. Levay (STScI)

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