Little Red Dots as Globular Clusters in Formation
7 affiliations
- 1The University of Texas at Austin
- 2Center for Astrophysics
- 3Max-Planck-Institut für Astronomie
- 4Institute of Science and Technology Austria (ISTA)
- 5MIT Kavli Institute for Astrophysics and Space Research
- 6Universität Heidelberg
- 7Zentrum für Astronomie der Universität Heidelberg
Abstract
Little Red Dots (LRDs), among the most enigmatic high-redshift discoveries by JWST, are commonly believed to be powered by accreting supermassive black holes. Here, we explore the possibility that these sources are globular clusters in formation, with rest-frame UV arising from a very young stellar population and rest-frame optical from a short-lived supermassive (>10 4 M ⊙ ) star. The spectral profiles of LRDs are broadly consistent with this scenario, though the observed temperatures and bolometric luminosities favor emission reprocessed by optically thick continuum-driven winds not fully captured by current models. The LRD z ∼ 5−7 UV luminosity function naturally evolves, under standard evolutionary and mass-loss prescriptions, into a present-day mass function with a turnover at log 10 ( M * / M ⊙ ) = 5.3 and an exponential cutoff at high masses, consistent with local globular cluster populations. We estimate the total present-day number density of LRDs formed across all redshifts to be ≈0.3 Mpc −3 , similar within uncertainties to local globular clusters. The observed LRD redshift range matches the age distribution of metal-poor globular clusters, without current LRD counterparts to the metal-rich population. If LRDs are globular clusters in formation, we predict chemical abundance patterns characteristic of multiple stellar populations, including enhanced He and N, and potential Na–O and Al–Mg anticorrelations. These results offer a local perspective to explore this surprisingly abundant population of distant sources, and a potential new window into extreme stellar astrophysics in the early Universe.
Related
- A Cosmological Framework for Stellar Collisions at High Redshift in Proto-globular Clusters, Nuclear Star Clusters, and Little Red Dots
- Formation of Heavy Seed Black Holes and Little Red Dots-like Compact Clusters in Metal-enriched Star-forming Regions
- The Ashes of Supermassive Stars: Globular Cluster-like Aluminum Enhancement in Little Red Dots
- Mass and Spin Growth of Very Massive Stars in Star Clusters Potentially Associated with Little Red Dots
- From Feedback-free Star Clusters to Little Red Dots via Compaction
BibTeX
@article{chisholm2026little,
title = {{Little Red Dots as Globular Clusters in Formation}},
author = {John Chisholm and Danielle A. Berg and Michael Boylan-Kolchin and Anna de Graaff and Lukas J. Furtak and Vasily Kokorev and Jorryt Matthee and Julián B. Muñoz and Rohan P. Naidu and Andreas A. C. Sander},
journal = {The Astrophysical Journal Letters},
year = {2026},
month = jun,
doi = {10.3847/2041-8213/ae6dae},
url = {https://doi.org/10.3847/2041-8213/ae6dae},
note = {CC BY},
}
RIS
TY - JOUR
TI - Little Red Dots as Globular Clusters in Formation
AU - John Chisholm
AU - Danielle A. Berg
AU - Michael Boylan-Kolchin
AU - Anna de Graaff
AU - Lukas J. Furtak
AU - Vasily Kokorev
AU - Jorryt Matthee
AU - Julián B. Muñoz
AU - Rohan P. Naidu
AU - Andreas A. C. Sander
PY - 2026
DA - 2026/06/02
JO - The Astrophysical Journal Letters
DO - 10.3847/2041-8213/ae6dae
UR - https://doi.org/10.3847/2041-8213/ae6dae
AB - Little Red Dots (LRDs), among the most enigmatic high-redshift discoveries by JWST, are commonly believed to be powered by accreting supermassive black holes. Here, we explore the possibility that these sources are globular clusters in formation, with rest-frame UV arising from a very young stellar population and rest-frame optical from a short-lived supermassive (>10 4 M ⊙ ) star. The spectral profiles of LRDs are broadly consistent with this scenario, though the observed temperatures and bolometric luminosities favor emission reprocessed by optically thick continuum-driven winds not fully captured by current models. The LRD z ∼ 5−7 UV luminosity function naturally evolves, under standard evolutionary and mass-loss prescriptions, into a present-day mass function with a turnover at log 10 ( M * / M ⊙ ) = 5.3 and an exponential cutoff at high masses, consistent with local globular cluster populations. We estimate the total present-day number density of LRDs formed across all redshifts to be ≈0.3 Mpc −3 , similar within uncertainties to local globular clusters. The observed LRD redshift range matches the age distribution of metal-poor globular clusters, without current LRD counterparts to the metal-rich population. If LRDs are globular clusters in formation, we predict chemical abundance patterns characteristic of multiple stellar populations, including enhanced He and N, and potential Na–O and Al–Mg anticorrelations. These results offer a local perspective to explore this surprisingly abundant population of distant sources, and a potential new window into extreme stellar astrophysics in the early Universe.
SN - 2041-8205
SN - 2041-8213
ER -