Using Ap stars as LABoratories for probing chemical transport mechanisms, with ultra-precise space-based photometry (ApLAB)


Principal Investigator: Margarida Cunha


Fundação para a Ciência e a Tecnologia

Over the last decades, asteroseismology has blossomed thanks to the ultra-precise, space-based photometric time series acquired by satellites such as CoRoT (France/ESA; 2006-2012), Kepler/K2 (NASA; 2009-2018), and TESS (NASA; 2018-present). Through the study of stellar oscillations, major progress has been made in the understanding of fundamental aspects of the physics that govern stellar evolution. Nevertheless, the modelling of stars and their evolution across the HR diagram still faces outstanding challenges, related to unresolved questions pertaining to the transport of chemical elements inside stars. These, in turn, limit the accuracy with which stellar fundamental properties can be inferred, with negative implications for a diversity of astrophysical studies, including exoplanetary research and Galactic archaeology. The exquisite seismic data that are being acquired by the TESS survey, on a large number of pulsating, chemically peculiar (so-called roAp) stars, potentiates a major breakthrough in the understanding of these transport mechanisms that impact the modelling of all stars and the inference of accurate stellar fundamental properties. Based on a strong synergy between theory and observations, the project will focus on the exploitation of the TESS data on roAp stars, using these data to set quantitative constraints on the efficiency of the chemical mixing inside these stars and furthering our understanding of the driving of their pulsations. Further to this, it will launch a living catalogue of roAp stars, that the team plans to keep updated as TESS data continue to be acquired beyond the project term. It will bring together seismic, classical, and fundamental properties inferred from state-of the-art stellar evolution models, that will be a legacy for a myriad of future studies directed towards improving the modelling of stars and their pulsations. In the long run, our results will also have a far-reaching impact on studies that depend directly on the accurate modelling of stars, including studies aimed at the characterization of exoplanetary systems or at reconstructing the history of the Milky Way.

Total funding: € 49.196,48