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    "story_id": "mp-2026-08-10-001",
    "source_story_id": "tmp-lead-capotauro-proper-motion",
    "edition_id": "mp-2026-08-10-morning-0032",
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    "headline": "The Earliest Galaxy Walked Across the Sky",
    "slug": "the-earliest-galaxy-walked-across-the-sky",
    "dek": "A red JWST source once proposed as a galaxy at redshift 32 moved against its background, identifying it instead as a cold Milky Way brown dwarf.",
    "summary": "A red JWST source once proposed as a galaxy at redshift 32 moved against its background, identifying it instead as a cold Milky Way brown dwarf.",
    "body_text": "Researchers compared new JWST medium-band imaging with discovery observations separated by about 3.5 years and measured Capotauro moving 132 plus or minus 20 milliarcseconds relative to 68 compact reference sources. That motion rules out an extragalactic object at more than six sigma, according to the preprint. Template fitting instead favors a roughly 350-kelvin Y-type brown dwarf about 730 parsecs away. The result shows why multi-epoch imaging matters when unresolved cool stars imitate extreme early-galaxy colors; it remains an author-reported preprint submitted to MNRAS.",
    "why_it_matters": "A red JWST source once proposed as a galaxy at redshift 32 moved against its background, identifying it instead as a cold Milky Way brown dwarf.",
    "limitations": [
      "That motion rules out an extragalactic object at more than six sigma, according to the preprint."
    ],
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    "first_published_at": "2026-08-10T09:00:00.000-04:00",
    "modified_at": "2026-08-10T15:50:00.000-04:00",
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        "text": "A red JWST source once proposed as a galaxy at redshift 32 moved against its background, identifying it instead as a cold Milky Way brown dwarf.",
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        "qualification": "That motion rules out an extragalactic object at more than six sigma, according to the preprint."
      }
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    "source_ids": [
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    "tags": [
      "JWST",
      "brown dwarfs",
      "proper motion",
      "early galaxies"
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    "image_url": "https://themachinepress.com/issues/2026-08-10/lead-capotauro-proper-motion.png",
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  "sources": [
    {
      "source_id": "source-2026-08-10-001",
      "title": "arXiv preprint 2608.07461",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.07461",
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      "source_type": "primary_research",
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      "published_at": "2026-08-07T13:00:00.000-04:00",
      "accessed_at": "2026-08-10T15:30:00.000-04:00",
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    "name": "The Machine Press",
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    "title": "The Earliest Galaxy Walked Across the Sky",
    "publisher": "The Machine Press",
    "published_at": "2026-08-10T09:00:00.000-04:00",
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