{
  "abstract": "GRB 221009A, the Brightest Of All Time (BOAT), presents a challenge for afterglow modelling due to its low Galactic latitude and consequent high line-of-sight extinction. This has led to a wide range of conflicting values for the optical spectral index and dust extinction in the literature. We present a re-analysis of the afterglow spectra, using VLT X-Shooter data at 0.5, 4, and 10.5 days, and JWST NIRSpec$/$MIRI data at 13.3 days post-burst. We fit the data with single and smoothly broken power-law models and perform a joint fit with a double smoothly broken power-law (DSBPL) across all epochs. Our analysis reveals a strong degeneracy between the assumed extinction and the inferred intrinsic spectral index, particularly in the optical, explaining the diversity of previous results. The joint DSBPL fit yields a total line-of-sight extinction of $A_{V} = 4.40 \\pm 0.01$ and a blue continuum, with an intrinsic spectral index of $β= 0.447 \\pm 0.001$. Although marginally preferred by the spectral fits, a wind medium can be rejected by the temporal evolution of the afterglow light curve. The fit spectral index and temporal decline are only consistent with a uniform density medium if an early jet break at $\\sim 0.5-1.0$ days is invoked. Our results imply a hard electron distribution index of $p = 1.89 < 2$, challenging standard particle acceleration models and suggesting a narrow, energetic jet core dominates the early optical-to-X-ray emission.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.29022",
  "author_total": 9,
  "authors": [
    {
      "name": "Nguyen M. Khang"
    },
    {
      "name": "Gavin P. Lamb"
    },
    {
      "name": "Helena-M. S. Grabham"
    },
    {
      "name": "Conor M. B. Omand"
    },
    {
      "name": "Hamid Hamidani"
    },
    {
      "name": "Andrew J. Levan"
    },
    {
      "name": "Nial R. Tanvir"
    },
    {
      "name": "Valerio D'Elia"
    },
    {
      "name": "Luca Izzo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0hnepaey121xr.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.29022",
  "fulltext_url": null,
  "id": "0hnepaey121xr",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.29022",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2605.29022",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0hnepaey121xr.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T18:21:30Z",
      "native_id": "2605.29022",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.29022"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "JWST's Dusty Blue BOAT -- GRB 221009A",
  "title_text": "JWST's Dusty Blue BOAT -- GRB 221009A",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:33Z",
  "url": "https://research.draconitic.com/paper/0hnepaey121xr",
  "venue": "arXiv",
  "versions": []
}