Tracing the Milky Way: calibrating chemical ages with high-precision <i>Kepler</i> data
ABSTRACT Chemical clocks offer a powerful tool for estimating stellar ages from spectroscopic surveys. We present a new detailed spectroscopic analysis of 68 Kepler red giant stars to provide a suite of high-precision abundances along with asteroseismic ages with better than 10 per cent precision from individual mode frequencies. We obtained several chemical clocks as ratios between s-process elements (Y, Zr, Ba, La, and Ce) and $\alpha$-elements (Mg, Ca, Si, Al, and Ti). Our data show that [Ce/Mg] and [Zr/Ti] display a remarkably tight correlation with stellar ages, with abundance dispersions of 0.08 and 0.01 dex, respectively, and below 3 Gyr in ages, across the entire Galactic chronochemical history. While improving the precision floor of spectroscopic surveys is critical for broadening the scope and applicability of chemical clocks, the intrinsic accuracy of our relations – enabled by high-resolution chemical abundances and stellar ages in our sample – allows us to draw meaningful conclusions about age trends across stellar populations. By applying our relations to the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and Gaia-ESO surveys, we are able to differentiate the low- and high-$\alpha$ sequences in age, recover the age–metallicity relation, observe the disc flaring of the Milky Way, and identify a population of old metal-rich stars.
Authors
- E. Willett (ORCID: https://orcid.org/0000-0002-7831-1402)
- L. Magrini (ORCID: https://orcid.org/0000-0003-4486-6802)
- V. Grisoni (ORCID: https://orcid.org/0000-0001-7366-7699)
- A. Miglio (ORCID: https://orcid.org/0000-0001-5998-8533)
- C. Chiappini (ORCID: https://orcid.org/0000-0003-1269-7282)
- K. Brogaard (ORCID: https://orcid.org/0000-0003-2001-0276)
- Amalie Stokholm (ORCID: https://orcid.org/0000-0002-5496-365X)
- M. Matteuzzi (ORCID: https://orcid.org/0000-0003-2580-7014)
- J.M. Prats-Montalbán (ORCID: https://orcid.org/0000-0001-6294-4486)
- G. Casali (ORCID: https://orcid.org/0000-0002-8173-4000)
- A. Bragaglia (ORCID: https://orcid.org/0000-0002-0338-7883)
- L. Casagrande (ORCID: https://orcid.org/0000-0003-2688-7511)
- M. Tailo (ORCID: https://orcid.org/0000-0002-1128-098X)
Institutions
- Australian National University (AU)
- Aarhus University (DK)
- Leibniz Institute for Astrophysics Potsdam (DE)
- Arcetri Astrophysical Observatory (IT)
- Astronomical Observatory of Rome (IT)
- Trieste Astronomical Observatory (IT)
- Osservatorio astronomico di Bologna (IT)
- Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna (IT)
- ASTRO-3D (AU)
- Osservatorio Astrofisico di Catania (IT)
- Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (IT)
- ARC Centre of Excellence for All-sky Astrophysics (AU)
- Osservatorio Astronomico di Padova (IT)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Birmingham (GB)
- National Institute for Astrophysics (IT)
- University of Bologna (IT)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2025-06-28
- DOI
- https://doi.org/10.1093/mnras/staf1047
- Citations
- 3
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 3.46
Funders
- Aarhus Universitet
- European Commission
- Istituto Nazionale di Astrofisica
- Universitetet i Oslo
- Háskóli Íslands
- Turun Yliopisto
- Stockholms Universitet
- Institut sur la Nutrition et les Aliments Fonctionnels
- H2020 European Research Council