How can we finally see the first light? Status and perspective in the search for Population III stars
Finding the first (Population III or Pop III) stars is one of the fundamental quests of astronomy, aiming to deliver the missing link in how stars form at early cosmic times. Yet their initial mass function, formation sites and feedback remain highly uncertain, as well as the timing and topology of the transition to metal-enriched star formation. The observability of their peculiar spectral features is also debated, due to their short lifetime and faintness. This review summarizes current theoretical expectations for Pop III star formation, and the main observational strategies that have been adopted to constrain their properties across cosmic time, including near-field cosmology studies, direct searches for extremely metal-poor star-forming complexes and/or hard-ionizing spectral signatures at high and intermediate redshifts, and prospects for identifying Pop III activity up to Cosmic Dawn. The combination of JWST spectroscopy, time-domain searches, lensing surveys, stellar archaeology, absorption-line studies, as well as improved simulations, is yielding a growing number of observational candidates and narrowing the allowed parameter space for the first stars, setting the stage for a ‘’golden era’’ of Pop III searches.
Authors
- Mauro Giavalisco (ORCID: https://orcid.org/0000-0002-7831-8751)
- Fabio Pacucci (ORCID: https://orcid.org/0000-0001-9879-7780)
- D. Scholte (ORCID: https://orcid.org/0000-0002-6867-1244)
- C. Charbonnel (ORCID: https://orcid.org/0000-0002-6449-6194)
- Alessandra Venditti (ORCID: https://orcid.org/0000-0003-2237-0777)
- M. Castellano (ORCID: https://orcid.org/0000-0001-9875-8263)
- Yoshihisa Asada (ORCID: https://orcid.org/0000-0003-3983-5438)
- Anatole Storck (ORCID: https://orcid.org/0009-0000-3245-7951)
- Karina Caputi
- A J Bunker (ORCID: https://orcid.org/0000-0002-8651-9879)
- P G Pérez-González
- S Fujimoto
- A Ferrara
- Laure Ciesla
- Harley Katz
- Stefania Salvadori
- Josephine Baggen
- Chiaki Kobayashi
- Daniel Schaerer
- Eros Vanzella
- Paola Santini
- Erik Zackrisson
- Pratika Dayal
- Volker Bromm
- Alessandro Trinca
- Hakim Atek
- Roberto Maiolino
- Raffaella Schneider
- Julian B. Muñoz
Institutions
- University of Geneva (CH)
- Uppsala University (SE)
- University of Hertfordshire (GB)
- Scuola Normale Superiore (IT)
- University of Groningen (NL)
- Aix-Marseille Université (FR)
- University of Cambridge (GB)
- University of Massachusetts Amherst (US)
- Astronomical Observatory of Rome (IT)
- Yale University (US)
- Sorbonne Université (FR)
- University of Oxford (GB)
- University of Chicago (US)
- Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna (IT)
- Canadian Institute for Theoretical Astrophysics (CA)
- Center for Astrophysics Harvard & Smithsonian (US)
- Centro de Astrobiología (ES)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Florence (IT)
- Sapienza University of Rome (IT)
- The University of Texas at Austin (US)
- University of Edinburgh (GB)
Publication Details
- Journal
- The Open Journal of Astrophysics
- Published
- 2026-08-20
- DOI
- https://doi.org/10.33232/001c.167811
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00