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    "headline": "The Supernova’s Shape Remembered Its Progenitor’s Age",
    "slug": "the-supernova-s-shape-remembered-its-progenitor-s-age",
    "dek": "Local stellar age correlated about −0.71 with Type Ia light-curve shape, while color showed no significant relation.",
    "summary": "Local stellar age correlated about −0.71 with Type Ia light-curve shape, while color showed no significant relation.",
    "body_text": "In a volume-limited Type Ia supernova sample, the modeled progenitor-age distribution and light-curve-shape distribution shared young and old components that evolved with redshift. Local age at the explosion site correlated about −0.71 with the x1 shape parameter, compared with about 0.08 for color. An empirical mapping reproduced x1 distributions across redshift bins. The result supports population-level age control for cosmology samples; local age remains a proxy rather than a direct measurement of each progenitor.",
    "why_it_matters": "Local stellar age correlated about −0.71 with Type Ia light-curve shape, while color showed no significant relation.",
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    "modified_at": "2026-09-14T09:00:00.000-04:00",
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        "text": "Local stellar age correlated about −0.71 with Type Ia light-curve shape, while color showed no significant relation.",
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    "tags": [
      "Type Ia supernovae",
      "stellar populations",
      "cosmology"
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  "sources": [
    {
      "source_id": "source-2026-09-14-020",
      "title": "arXiv preprint 2609.12083",
      "publisher": "arXiv",
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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": "The Supernova’s Shape Remembered Its Progenitor’s Age",
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