A dust-free hierarchically nested supermassive-star model for James Webb Space Telescope Little Red Dots

Pau Amaro Seoane

First listed 2026-07-24 | Last updated 2026-07-24

Abstract

Short digest

Amaro Seoane proposes a dust-free interpretation for the dust-poor subset of JWST little red dots: a hierarchically nested supermassive-star configuration in which a radiation-dominated envelope encloses a trapped nuclear star cluster and dense secondary core. Magnetic support driven by plunging stars inflates and cools the primary envelope to produce the red optical continuum, while unobscured infalling stars supply the blue UV excess; the Compton-thick nested core both thermalizes X-rays and generates broad hydrogen-line wings. The model links these spectral and multiwavelength signatures to rapid seed growth under the host envelope's global radiation limit, potentially reducing assembly from hundreds to tens of millions of years, though it is presented as a qualitative physical framework rather than a direct fit to an LRD sample.

Key figures to inspect

• Figure 1. This evolutionary timeline establishes the paper's central nested-supermassive-star sequence, from gas accumulation and stellar capture through secondary-core formation, black-hole collapse, and the proposed rapid accretion phase. It is the clearest schematic of how the individual spectral and growth arguments are intended to fit into one physical channel.
• Figure 2. This is the key dust-free continuum diagnostic. The left panel shows the claimed magnetic inflation of the radiation-dominated envelope relative to an unmagnetized polytrope, while the right panel connects the cooled envelope plus unshielded cluster stars to the defining red-optical and blue-UV V-shaped LRD spectrum.
• Figure 3. This figure carries the model's broad-line and X-ray-obscuration-facing physical picture through the secondary core. Its damped settling calculation and synthetic hydrogen profile illustrate how virialized debris can create broad Balmer wings while an initially expanding, unvirialized component produces a narrow absorption trough.