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    "story_id": "mp-2026-09-23-006",
    "source_story_id": "tmp-story-parker-fast-wind-subalfvenic",
    "edition_id": "mp-2026-09-23-morning-0076",
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    "headline": "Parker Sampled Fast Wind Below the Alfvén Surface",
    "slug": "parker-sampled-fast-wind-below-the-alfven-surface",
    "dek": "The extended stream looked like polar-coronal-hole wind about ten solar radii out.",
    "summary": "The extended stream looked like polar-coronal-hole wind about ten solar radii out.",
    "body_text": "Near its 23rd perihelion, Parker Solar Probe sampled an extended sub-Alfvénic interval at roughly ten solar radii with speeds mostly above 400 kilometers per second. The authors identify it as the first polar-coronal-hole-like fast stream observed inside the sub-Alfvénic corona. Its turbulence was already developed, strongly transverse and highly imbalanced despite the close distance. The source is inferred as a large equatorial coronal hole rather than directly traced to a polar hole.",
    "why_it_matters": "The extended stream looked like polar-coronal-hole wind about ten solar radii out.",
    "limitations": [],
    "importance": 9,
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    "first_published_at": "2026-09-23T09:00:00.000-04:00",
    "modified_at": "2026-09-23T09:00:00.000-04:00",
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        "text": "The extended stream looked like polar-coronal-hole wind about ten solar radii out.",
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        "qualification": null
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    "source_ids": [
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    "tags": [
      "Parker Solar Probe",
      "solar wind",
      "turbulence"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-09-23-006",
      "title": "arXiv preprint 2609.26720",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.26720",
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      "source_type": "primary_research",
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      "published_at": "2026-09-22T13:07:25.000-04:00",
      "accessed_at": "2026-09-23T08:22:43.661-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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    "title": "Parker Sampled Fast Wind Below the Alfvén Surface",
    "publisher": "The Machine Press",
    "published_at": "2026-09-23T09:00:00.000-04:00",
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