Age-Dating Stars

The determination of stellar ages is crucial for the development of our understanding of the universe and for constraining theoretical models of galaxy formation and planetary system evolution. The ages of stars provide scientists with timescales to identify the relevant physical processes responsible for the development of the cosmic structures.

Age-dating stars describes in a simple, yet rigorous manner, the vast array of techniques used to determine stellar ages. It also explores how these ages inform our knowledge about planets, star clusters, galaxies and even distant galaxies that we cannot resolve into individual stars. Up-to-date with the latest research and technologies in the field, it discusses open problems that remain to be pondered in future research. This second edition includes a new, comprehensive introduction to the main concepts of asteroseismology, the use of asteroseismic observations for age determination and for probing the internal structure of stars, an updated analysis of the uncertainties on the age estimates, new results about the ages of stellar populations in our galaxy and high-redshift galaxies gathered observations from the Gaia satellite and the James Webb Space Telescope, and the new/upcoming observational facilities relevant to the subject. • Presents an entertaining and accessible approach whilst also providing a rigorous and comprehensive presentation of the subject. • Describes how to unveil the ages of stellar populations in the universe, even in distant galaxies that we cannot resolve into individual stars. • Contains historical notes about these techniques, outstanding major problems, and a discussion on future developments in the field.

It will be of interest to undergraduates and graduate students studying astronomy, and to readers from diverse backgrounds.

Author Biography

Maurizio Salaris is Professor of Stellar Astrophysics at the Liverpool John Moores University (UK), and works mainly on stellar evolution modelling, the study of Milky Way and extragalactic stellar populations. He was born in Rome, Italy, at the height of the space race, and grew up absorbing a healthy dose of TV footage of astronauts going into space and walking on the Moon, science-fiction series, movies and books, and space music from Germany and England. The final outcome of this upbringing was an early decision to become an astrophysicist (while playing drums in a band and doing athletics on the side), after toying with the ideas to be either a bus driver or a professional athlete. After studying physics at La Sapienza University in Rome, he worked at what is now named Osservatorio Astronomico d’Abruzzo (Italy), the Institute for Space Studies of Catalonia (Spain), and the Max Planck Institute for Astrophysics (Germany, as a Marie Curie Fellow), before spending the last 28 years at the Astrophysics Research Institute of the Liverpool John Moores University.

Prof. Salaris has published 270 papers in peer-reviewed astrophysics journals, plus dozens of conference proceedings. On the side, he enjoyed writing the textbooks Evolution of stars and stellar populations (Wiley, 2008), Old stellar populations (Wiley-VCH, 2013), the first edition of this Age-dating stars: From the Sun to distant galaxies (Taylor and Francis 2021), and more recently, an entry (on white dwarf structure and evolution) in the Encyclopaedia of Astrophysics (Elsevier, 2025). He also had fun writing, starring, and co-producing a series of educational science fiction short videos. Prof. Salaris is a fellow of the Royal Astronomical Society and the Higher Education Academy (UK), a member of the International Astronomical Union and the European Astronomical Society, and Associate Editor of Astronomy & Astrophysics, one of the top peer-reviewed international astrophysics journals.