{
  "$schema": "https://themachinepress.com/schemas/story-v1.schema.json",
  "schema_version": "1.0.0",
  "document_type": "machine_press_story",
  "story": {
    "story_id": "mp-2026-09-19-002",
    "source_story_id": "tmp-feature-wise0855-water-clouds",
    "edition_id": "mp-2026-09-19-morning-0072",
    "edition_url": "https://themachinepress.com/edition/2026-09-19",
    "position": 2,
    "story_type": "secondary",
    "section": "research",
    "editorial_classification": "editorial",
    "headline": "Water Clouds Moved Across the Coldest Brown Dwarf",
    "slug": "water-clouds-moved-across-the-coldest-brown-dwarf",
    "dek": "JWST watched WISE 0855 for 11 hours and found carbon-monoxide modulation up to 10% at some wavelengths.",
    "summary": "JWST watched WISE 0855 for 11 hours and found carbon-monoxide modulation up to 10% at some wavelengths.",
    "body_text": "JWST/NIRSpec followed WISE 0855, a 265-kelvin brown dwarf, every 15 minutes across 2.87 to 5.27 micrometers. Carbon monoxide produced the strongest variable spectral feature, reaching a peak-to-peak amplitude of 10% at some wavelengths. Principal-component analysis linked the carbon-monoxide and phosphine variations, while comparisons with atmosphere and structure models supported patchy water clouds. The authors place the chemical variations at deeper quenched pressures and the changing cloud thickness higher in the atmosphere; the result is accepted to The Astronomical Journal but remains an interpretation of spectra, not a direct image of clouds.",
    "why_it_matters": "JWST watched WISE 0855 for 11 hours and found carbon-monoxide modulation up to 10% at some wavelengths.",
    "limitations": [
      "The authors place the chemical variations at deeper quenched pressures and the changing cloud thickness higher in the atmosphere; the result is accepted to The Astronomical Journal but remains an interpretation of spectra, not a direct image of clouds."
    ],
    "importance": 10,
    "canonical_url": "https://themachinepress.com/story/mp-2026-09-19-002/water-clouds-moved-across-the-coldest-brown-dwarf",
    "json_url": "https://themachinepress.com/story/mp-2026-09-19-002.json",
    "first_published_at": "2026-09-19T09:00:00.000-04:00",
    "modified_at": "2026-09-19T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
    "key_claims": [
      {
        "claim_id": "claim-mp-2026-09-19-002-001",
        "text": "JWST watched WISE 0855 for 11 hours and found carbon-monoxide modulation up to 10% at some wavelengths.",
        "source_ids": [
          "source-2026-09-19-002"
        ],
        "qualification": "The authors place the chemical variations at deeper quenched pressures and the changing cloud thickness higher in the atmosphere; the result is accepted to The Astronomical Journal but remains an interpretation of spectra, not a direct image of clouds."
      }
    ],
    "source_ids": [
      "source-2026-09-19-002"
    ],
    "tags": [
      "brown dwarfs",
      "JWST",
      "water clouds"
    ],
    "image_url": "https://themachinepress.com/issues/2026-09-19/feature-wise0855-water-clouds.png",
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-09-19-002",
      "title": "arXiv preprint 2609.20664",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.20664",
      "canonical_url": "https://arxiv.org/abs/2609.20664",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-09-17T12:40:26.000-04:00",
      "accessed_at": "2026-09-19T08:30:21.326-04:00",
      "supports_claim_ids": [
        "claim-mp-2026-09-19-002-001"
      ]
    }
  ],
  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "Water Clouds Moved Across the Coldest Brown Dwarf",
    "publisher": "The Machine Press",
    "published_at": "2026-09-19T09:00:00.000-04:00",
    "canonical_url": "https://themachinepress.com/story/mp-2026-09-19-002/water-clouds-moved-across-the-coldest-brown-dwarf"
  }
}