Bill's research interests are focused on the study of the Sun and other Sun-like stars, with a particular interest in using asteroseismology to characterize newly discovered exoplanet systems with Sun-like hosts. He has leadership positions in Kepler/K2, TESS and PLATO, and is the principal-investigator on the BiSON project.
The common thread of Andrea's research activities is the development and application of asteroseismic techniques to infer details about the internal structure of stars, and to determine precise and accurate properties of large ensembles of stars, which are key to understanding the formation and chemo-dynamical evolution of our Galaxy.
Guy is a lecturer at the University of Birmingham and he is interested in researching the nature of the Sun, stars that are a little bit like the Sun, and stars that are much more evolved than the Sun. He is interested in the evolution of stars and how the rotation, magnetism, and mass loss of stars evolves with time. Guy uses observations of the oscillations of the Sun and the stars to learn about stellar evolution and to characterise the fundamental properties of stars. The use of oscillations can be particularly valuable when studying stars that host extrasolar planets. Guy is also involved with the daily operations of the BiSON project.
Yvonne has previously been the head of the group and is now part-time and fully engaged with research. There are two primary strands to her research. The first is in helioseismology - the study of the interior of the Sun through the sound waves that propagate there. Associated with this is a strong interest in the instrumentation that enables the observations i.e., BiSON. The second strand is measurement of asteroseismic parameters and their use in the determination of the internal structure of red giants stars as key tracers of the structure of the galaxy. Yvonne is a Fellow of the Royal Society and currently vice-president of the Royal Astronomical Society.
In January 2020 Yvonne received the RAS Gold Medal. This is the highest award in the Society's gift, awarded for her achievements in helioseismology.
A regular visitor to observatories in the Atacama desert, Amaury is the discoverer of over one hundred exoplanets. His observations focus on planetary systems that are different compared to our own, either by the type of planets that compose those systems, by their architectures, or because of the type of star(s) they orbit. As part of the SPECULOOS collaboration, he now searches for planets the same size and the same temperature as the Earth and aims to find out if life emerged elsewhere in the Universe. The first such examples were found in the TRAPPIST-1 system.
In January 2020 Amaury received the Fowler award from the Royal Astronomical Society, and was named a finalist in the Blavatnik awards. Both recognise the important work done by young researchers across all of the physical sciences and engineering.
Warrick is a Research Fellow, and he is broadly interested in stellar modelling as a physical, numerical and mathematical problem. He has experience with computing models and their oscillations with several different codes. He uses asteroseismology of solar-like oscillators to improve stellar models, focusing most recently on models of near-surface convection in Sun-like stars.
Dr Rachel Howe
Rachel's main interests are the changes in the properties of solar oscillation modes in response to solar activity and the changes in the Sun's interior rotation over the solar cycle - in particular the pattern of migrating faster and slower flows known as the torsional oscillation. She is also interested in helioseismology using different observables such as the UV observations from SDO/AIA.
Dr Andreas Joergensen
Through his research, Andreas aims to obtain a more realistic depiction and a better understanding of low-mass stars. For this purpose, he combines state-of-the-art stellar structure and evolution codes with multi-dimensional magneto-hydrodynamic (MHD) simulations of convective envelopes. The resulting hybrid models successfully mimic the underlying MHD simulations. They recover asteroseismic observations with high accuracy and overcome degeneracies that haunt the standard procedure.
Andreas is currently extending his analysis to include more evolved stars and to evaluate the implications for galactic archaeology. In short, he thus addresses the following questions: What is the nature of MHD processes in stars? How does the treatment of hydrodynamic processes affect stellar structure models and their evolution? How does this affect stellar parameter estimates? Which ramifications does this have for other fields that draw on stellar physics? How can tensions between models and data be corrected for and what insight do such tensions yield?
Dr Tanda Li
Tanda is currently a research fellow in the School and is focusing on theoretical modelling of solar-like oscillations. Tanda received his PhD degree in Beijing Normal University in 2008, and worked for National Astronomical Observatory in Beijing and University of Sydney afterwards. Tanda moved to Birmingham and joined the Solar & Stellar group in September 2019. Tanda's major interest is using asteroseismic modelling to provide accurate global parameters and internal structures for stars presenting solar-like oscillations. Recent researches include seismic mode identification and the modelling of Kepler subgiants and red giants, the ages of subgiants in Kepler and TESS field, and establishing theoretical model database for solar-like oscillators.
Dr Ted Mackereth
Ted works on using data for stars in the Milky Way to understand its history of formation and evolution. In particular, he uses astrometric data from the ESA Gaia mission in combination with detailed spectroscopic data such as that from the SDSS-APOGEE survey, to understand the stellar populations which make up the Galactic disc. His more recent interests are in using asteroseismology to make accurate measurements of stellar ages, and how we can use what we find out to understand the Milky Way in context amongst other galaxies in the Universe.
Dr Josefina Montalbán Iglesias
Josefina works in the framework of the "Asterochronometry" ERC project. Her main activities consist in the computation of stellar modelling and their oscillations frequencies. Josefina is interested in low and intermediate mass stars, during their main sequence and red giant evolutionary phases. Josefina is also involved in the ESA PLATO mission, in the PSPM (PLATO Stellar Physics Management) Working Package.
Dr Martin Nielsen
Martin works on preparations for the ESA PLATO Mission, in particular the design, development and testing of "peak bagging" algorithms for extracting estimates of individual oscillation frequencies from PLATO data. This work involves use of machine-learning algorithms and hierarchical Bayesian models. Martin also works on analysing data from NASA's TESS spacecraft, and studying the rotation of stars similar to the Sun.
Dr Lalitha Sairam
Lalitha has worked extensively on both ground-based and space-based observations to understand the underlying physics of stellar atmospheres and their effects on orbiting exoplanets. Her focus areas include understanding stellar magnetic activity at the bottom of the main sequence. She also works on employing the computationally tractable probabilistic data analysis methods such as Gaussian processes to mitigate the effects of stellar activity on the planetary radial velocity signal. As part of the Solar & Stellar Physics group, Lalitha will be developing an analytical method to accurately measure the radial velocity of the double-line binaries.
Steven leads the operation and development of the international Birmingham Solar Oscillations Network (BiSON), a global network of automated robotic solar telescopes funded by the Science and Technology Facilities Council. His research interests are instrumentation and electronics, and high-resolution optical spectroscopy techniques.
Georgina is predominantly interested in exoplanets and how we can group them together. Classification of objects like stars, planets and moons allow us to make predictions about how they were formed and what they are made of. Georgina is looking at where exoplanets fit in with populations of well-studied objects in order to learn more about the atmospheres of exoplanets. This is particularly interesting, as better techniques to determine whether or not a planet has, for example, water in its atmosphere will allow us to spot potential candidates for sustaining life.
Oliver's research interests focus on exoplanets and the use of asteroseismology in extra-solar star system characterisation. For his final undergraduate project he used asteroseismology to find signatures of stellar activity in Kepler data, a line of research which he is currently continuing.
Alex is continuing on from her undergraduate project using asteroseismology to study the near-surface magnetic activity of stars. We know that the Sun has activity which manifests in bands of constant latitude and Alex is working on how we can use oscillations to constrain the distribution of activity on stars other than the Sun. She is also developing methods of "peak-bagging" stellar oscillation spectra, fitting complex parametric models to the data.
Eddie’s research is based around the themes of space weather and the solar interior-atmosphere connections. He is looking at utilising high-energy cosmic ray observations from the HiSPARC network for forecasting space weather and solar storms – events that can cause an increase in ionising radiation at Earth leading to societal and economic impacts due to the modern reliance on technology for critical infrastructure. Eddie is also looking at linkages between the solar interior and atmosphere.
Vedad’s research interests are on the observational characterisation of exoplanets, brown dwarfs, and low-mass stars using Bayesian data analysis techniques. In particular, he uses data from state-of-the-art instruments such as HARPS and ESPRESSO to look for relics of dynamical interaction through the Rossiter-McLaughlin effect, which may uncover clues to the formation of the system. Vedad is also involved in a new Doppler survey to hunt for planets orbiting close binary stars, which regularly sends him on observing missions to Chile and France.
Saniya’s research focuses on the core-helium burning stars in the red clump. These low-mass stars play a fundamental role for stellar physics, distance measurements, as well as Galactic Archaeology. The analysis of the asteroseismic data obtained from thousands of red-giant stars has led to considerable progress on the understanding of this evolutionary stage. Which brings us to her PhD subject: the detailed morphology of the red clump has just become accessible to thorough analysis thanks to these asteroseismic constraints. At the interface between data analysis and stellar modelling, she aims to unveil the fine structure of the red clump, in a relaxed manner – following the example of her favourite bear.
Matthew’s research interests focus on exoplanet discovery using the radial velocity method, specifically around binary star systems. Only a few of these “circumbinary” planets have been discovered so far, however many more are predicted to exist. Finding these predicted planets could help shed some light on how planetary systems form and evolve over time. To find these planets Matt gathers data from telescopes such as the High Accuracy Radial velocity Planet Searcher (HARPS) located at the La Silla Observatory in Chile.
Walter Van Rossem
Walter's primary research interest lies in stellar modelling and asteroseismology. Combining these two he is looking for asteroseismic signatures for stellar mergers using MESA and GYRE for stars a bit more massive than the Sun.
Lindsey’s research is based on using asteroseismology as a window into the evolution of stars. With the combination of asteroseismology on large, high-quality data sets and computationally advanced statistical techniques, we will gain a better understanding of stellar properties and therefore the structure and evolution of the galaxy. She is also working with the TESS Asteroseismic Science Operations Center to develop a photometry pipeline tailored towards providing high-precision data for asteroseismology on stars from the NASA TESS mission.
Alex is using machine learning with stellar models to speed up the inference of fundamental stellar parameters. Using asteroseismology from NASA’s Kepler and TESS missions with astrometry from ESA’s Gaia mission, he hopes to develop robust statistical methods to determine how helium abundance varies in the Milky Way. His other research interests include probing the physics of stellar interiors using asteroseismology and contributing to open source software in astronomy. One such software is the python package PBjam which, for example, he uses to measure the oscillation modes of exoplanet host stars and subgiants.
Emma Started working in the group during her Master’s project, during which she investigated the helium abundance in red clump stars. She is now working on asterochronometry – a project to measure the ages of stars more precisely and accurately using data from asteroseismology and other sources. These ages are important for many fields within astrophysics. For example, we can use them for galactic archaeology to understand the formation and evolution of the Milky Way and to study systems of planets around other stars.
Artist in Collaboration
Mrs Louise Barden (Secretary to the Group)