4D stars
© Kavli Price – Thomas Eckhoff
Stars are the source of radiation, chemistry and life in the Universe. Given its fundamental role in astrophysics, a great deal of effort has gone into observing stars, both from the ground and from space. Space asteroseismology, also known as the study of satellite earthquakes, provides transformative knowledge of the internal structure, evolution, dynamics and magnetism of stars. However, to deduce basic quantities of most objects in the Universe, such as age, chemical composition, and energy, almost all astrophysicists rely on simplified stellar models with only 1 spatial dimension, treating the star as if it were a perfect sphere. This approach, which neglects the flattening of stars due to rotation or other multidimensional dynamical processes in their interior, provides an unstable basis for astrophysics, introducing large uncertainties in stellar ages. The precise ages of stars are a dominant missing ingredient in understanding stellar and planetary evolution, the emergence of life, and the chemistry of our Universe.
“With 4D-STAR, the four of us are embarking on a long journey together, aiming to provide a solid new foundation for astrophysics, by building three-dimensional evolution models of rotating magnetic stars, calibrated by asteroseismology”. says coordinating researcher Conny Aerts. A leading figure in asteroseismology, he develops pioneering stellar models calibrated by observed earthquakes to constrain the rotation and mixing of stars. “This lifting of stellar models to higher dimensions optimally begins now, using asteroseismic data from thousands of stars in all dominant life phases.” she continues