Astronomy at the Open University 2020-2023

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Our research programme, Astronomy at The Open University, covers the breadth of cosmic evolution, from formation of the first stars and galaxies to the birth of planets now in the star-forming regions of the Milky Way Galaxy closest to the Sun. We do this research by observation, laboratory experiments, computer simulations and mathematical modelling. We use purpose-designed laboratories and instruments, and instruments on telescopes and spacecraft to make our observations and measurements. Our group is based in the School of Physical Sciences at The OU in Milton Keynes.So what are we trying to find out? We have 7 separate projects covering a variety of things on all astronomical size-scales, from searching for and learning about planets orbiting the Sun's near-neighbour stars to using the magnification caused by the "gravitational lensing" effect to detect ultra-high redshift galaxies. These latter, most distant observable objects were formed when the Universe was very young. We study the jets of energetic particles which are ejected from the accreting black holes at the centres of galaxies, and use our observations to deduce how the jets affect their host galaxies and surroundings. We also work out how the jets in an individual galaxy change over the history of the Universe. Similarly, we study the formation of dust and stars throughout the Universe's history. Within our own Galaxy we pay particular attention to the most massive stars, which have masses roughly 100 times that of the Sun. They are extremely luminous and short-lived by astronomical standards - i.e. 10s or 100s of millions of years, rather than billions of years like the Sun and other "normal" lower mass stars. The most massive stars eject a lot of the material from their outer layers, we observe how this affects the neighbouring regions of the Galaxy. We use huge archives of data generated in the SuperWASP search for planets transiting bright stars to measure the variability of stars themselves. Using the citizen science project https://www.zooniverse.org/projects/ajnorton/superwasp-variable-stars we classify variable stars, and use the results to identify new examples of rare types of variable stars, for example red stars on the point of merging to form a "red nova". We are looking for rocky planets which orbit very close to their host stars - i.e. planets whose year is only about 10 Earth-days or less. These are interesting because the intense heating from the nearby star causes the rock to melt or change into gas, so the star ends up shrouded in metal-rich gas originating on the planets' surface. This gives us a unique opportunity to measure the composition of the rocky surfaces of these planets. In the laboratory we take measurements of ices - of water, but also carbon-monoxide, carbon-dioxide, and more complicated molecules like methanol. Because interstellar space is so cold, these molecules exist in ice form there, as so-called astrophysical ices. By re-creating them in the lab we can interpret telescope observations of them and work out how the first complex organic molecules formed in the Universe. This allows us to prepare for the launch of the next great NASA/ESA space observatory: the James Webb Space Telescope. Finally we are involved in planning the requirements for ESA's ARIEL space telescope, which will measure the compositions of planets orbiting other stars.