Inferring precise and accurate ages of stars is fundamental to trace back the formation and evolution of galaxies, to constrain the age of the Universe, or to investigate numerous aspects of planetary system evolution. All these issues, so apparently distant, are closely related to our calibration and knowledge of the ages of the stars. Unfortunately, estimating the stellar age is very challenging because it cannot be directly measured. This symposium will bring together leading experts in different research areas (e.g. star and planetary formation and evolution, galaxy formation and evolution and cosmology) to explore stellar dating techniques and their implications for cosmology and astrophysics. The various methods of measuring stellar age will be discussed, including, e.g. improvement in isochrone fitting in the era of Gaia and the use of star clusters as benchmarks in age measurement, the application of asteroseismology to stellar ages, the power (and limit) of chemical clocks in inferring individual and statistical ages, the empirical methods related to lithium abundances, rotation and magnetic activity, such as gyrochronology, up to the only method able to provide a zero point in ages, e.g. cosmochronometry.

Programme

The symposium will be organized in six blocks, dedicated to the main proposed topics:

• Ages from Isochrones in the Era of Gaia: Methods, Results, and Limitations. This block will focus on the advancements in age determination using isochrones, including Gaia data. Consider emphasizing the results and discussing the current limitations and uncertainties. Discuss also the range of star clusters, from young associations to the oldest globular clusters.
• Ages from Asteroseismology: Current Results and Future Prospects. Highlight the results based on average seismic parameters, numax and deltanu, and the latest results obtained using individual mode frequencies, and discuss the role of future or proposed dedicated-space missions like PLATO and HAYDN.
• Ages from Empirical Relations: Results and Future Prospects. Cover empirical methods such as gyrochronology, magnetic activity and chemical indicators. Discuss recent results from large surveys and explore future improvements in these methods.
• Ages of Planet Host Stars: Stellar Ages and Planetary System Evolution. Focus on how stellar ages are related to the structure and evolution of planetary systems. Discuss implications for understanding exoplanets and their formation history.
• Ages for Cosmology: Cosmochronometry and Stellar Population Studies. Cover the use of stellar populations (e.g., white dwarfs, Population II and III stars, globular clusters) in cosmology. Address current results, challenges, and future prospects for using stellar ages to understand the cosmos.
• Discussion on a common age scale. In this concluding block, we will engage in a comprehensive discussion about the establishment of a common age scale. The session aims to synthesize insights from the previous blocks, exploring the various methods of age determination and discussing the definition and testing of a common age scale.

Invited speakers

• Anna Queiroz (IAC, Spain)
• Aldo Serenelli (ICE-CSIC, Spain)
• Camilla Danielski (INAF-Arcetri, Italy)
• Louis Amard (University of Geneva, Switzerland)
• Raúl Jiménez Tellado (University of Barcelona, Spain)
• TBD()

Scientific organisers

• Giada Casali (Chair, ANU, Australia)
• Laura Magrini (co-Chair, INAF Arcetri, Italy)
• Diane Feuillet (University of Uppsala, Sweden)
• Jason Sanders (UCL, UK)
• Andrea Miglio (University of Bologna, Italy)
• Tiago Campante (IA, University of Porto, Portugal)
• Vanessa Hill (Observatoire de la Côte d'Azur, France)
• Licia Verde (ICC, University of Barcelona, Spain)
• Diego Godoy Rivera (IAC, Spain)
• Lorenzo Spina (INAF Arcetri, Italy)
• Robin Jeffries (Keele University, UK)
• Katja Poppenhager (AIP, Germany)

Contact

• Giada Casali: giada.casali @ anu.edu.au
• Laura Magrini: laura.magrini @ inaf.it