article published yes Anna de Graaff author Raphael E Hviding author Rohan P Naidu author Jenny E Greene author Tim B Miller author Joel Leja author Jorryt J Matthee author 7439a258-f3c0-11ec-9501-9df22fe067200000-0003-2871-127X Gabriel Brammer author Harley Katz author Rachel Bezanson author Leindert A Boogaard author Sownak Bose author John Chisholm author Nikko J Cleri author Pratika Dayal author Robert Feldmann author Yoshinobu Fudamoto author Seiji Fujimoto author Lukas J Furtak author Karl Glazebrook author Rashmi Gottumukkala author Kasper E Heintz author Vasily Kokorev author Ivo Labbe author Michael V Maseda author Ian McConachie author Themiya Nanayakkara author Erica Nelson author Przemysław Nowaczyk author Pascal A Oesch author Hans-Walter Rix author David J Setton author Alberto Torralba Torregrosa author 018f0249-0e87-11f0-b167-cbce08fbd5410000-0001-5586-6950 Fabian Walter author Bingjie Wang author Andrea Weibel author Arjen van der Wel author JoMa department We construct and characterize a sample of 146 little red dots (LRDs) across 2.0<z<9.3, selecting all sources with v-shaped ultraviolet (UV)–optical continua from James Webb Space Telescope (JWST) NIRSpec/PRISM spectra and compact morphologies in NIRCam/F444W imaging. We show that LRD continuum spectra are well described by modified blackbodies across ∼ 0.4 − 1.0 µm, with typical T ∼ 5000 K (λpeak ∼ 0.65 µm) across 2 dex in luminosity, and a tail toward T ∼ 2000 K. LRDs therefore trace a locus in the Hertzsprung–Russell diagram that is analogous to stars on the Hayashi track, strongly supporting the picture that LRDs are active galactic nucleus (AGN) embedded in optically thick dense gas envelopes. Hotter LRDs with λpeak < 0.65 µm typically have strong Balmer breaks, redder UV slopes, and high optical luminosities; other LRDs show weak or no Balmer breaks, and wide variety in βUV and L5100. Crucially, we demonstrate that the UV– optical continua are strongly linked to the Hα, Hβ, [O iii], and O i line properties. There is a tight linear relation between the Hα and optical continuum luminosities, as well as Hα and O i λ8446, indicating that Balmer, O i, and optical emission must primarily be powered by the same source. The Balmer decrement increases strongly toward higher LHα, L5100, and Balmer break strength, providing key evidence for luminosity-dependent effects of collisional (de-)excitation and resonant scattering in the gaseous envelopes. In contrast, we show that [O iii] emission likely originates from star-forming host galaxies, with strong variation in the AGN-to-host ratio among the LRD population. Our work presents an empirical description of the nature and structure of LRDs, defining a new benchmark for ongoing LRD model developments. https://research-explorer.ista.ac.at/download/22960/23026/2026_MonthNoticesRAS_deGraaff.pdf application/pdfno Oxford University Press2026 eng 0035-8711 1365-2966 2511.2182010.1093/mnras/stag1567 5513 de Graaff A, Hviding RE, Naidu RP, Greene JE, Miller TB, Leja J, Matthee JJ, Brammer G, Katz H, Bezanson R, Boogaard LA, Bose S, Chisholm J, Cleri NJ, Dayal P, Feldmann R, Fudamoto Y, Fujimoto S, Furtak LJ, Glazebrook K, Gottumukkala R, Heintz KE, Kokorev V, Labbe I, Maseda MV, McConachie I, Nanayakkara T, Nelson E, Nowaczyk P, Oesch PA, Rix H-W, Setton DJ, Torralba Torregrosa A, Walter F, Wang B, Weibel A, van der Wel A. 2026. Little red dots host black hole stars: A unified family of gas-reddened AGN revealed by JWST/NIRSpec spectroscopy. Monthly Notices of the Royal Astronomical Society. 551(3), stag1567. de Graaff, Anna, Raphael E Hviding, Rohan P Naidu, Jenny E Greene, Tim B Miller, Joel Leja, Jorryt J Matthee, et al. “Little Red Dots Host Black Hole Stars: A Unified Family of Gas-Reddened AGN Revealed by JWST/NIRSpec Spectroscopy.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2026. <a href="https://doi.org/10.1093/mnras/stag1567">https://doi.org/10.1093/mnras/stag1567</a>. de Graaff A, Hviding RE, Naidu RP, et al. Little red dots host black hole stars: A unified family of gas-reddened AGN revealed by JWST/NIRSpec spectroscopy. <i>Monthly Notices of the Royal Astronomical Society</i>. 2026;551(3). doi:<a href="https://doi.org/10.1093/mnras/stag1567">10.1093/mnras/stag1567</a> A. de Graaff <i>et al.</i>, “Little red dots host black hole stars: A unified family of gas-reddened AGN revealed by JWST/NIRSpec spectroscopy,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 551, no. 3. Oxford University Press, 2026. de Graaff, A., Hviding, R. E., Naidu, R. P., Greene, J. E., Miller, T. B., Leja, J., … van der Wel, A. (2026). Little red dots host black hole stars: A unified family of gas-reddened AGN revealed by JWST/NIRSpec spectroscopy. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stag1567">https://doi.org/10.1093/mnras/stag1567</a> A. de Graaff, R.E. Hviding, R.P. Naidu, J.E. Greene, T.B. Miller, J. Leja, J.J. Matthee, G. Brammer, H. Katz, R. Bezanson, L.A. Boogaard, S. Bose, J. Chisholm, N.J. Cleri, P. Dayal, R. Feldmann, Y. Fudamoto, S. Fujimoto, L.J. Furtak, K. Glazebrook, R. Gottumukkala, K.E. Heintz, V. Kokorev, I. Labbe, M.V. Maseda, I. McConachie, T. Nanayakkara, E. Nelson, P. Nowaczyk, P.A. Oesch, H.-W. Rix, D.J. Setton, A. Torralba Torregrosa, F. Walter, B. Wang, A. Weibel, A. van der Wel, Monthly Notices of the Royal Astronomical Society 551 (2026). de Graaff, Anna, et al. “Little Red Dots Host Black Hole Stars: A Unified Family of Gas-Reddened AGN Revealed by JWST/NIRSpec Spectroscopy.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 551, no. 3, stag1567, Oxford University Press, 2026, doi:<a href="https://doi.org/10.1093/mnras/stag1567">10.1093/mnras/stag1567</a>. 229602026-09-17T11:06:40Z2026-10-01T11:31:16Z