{
  "vercy": "1.0-draft",
  "publication": {
    "status": "research-draft",
    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-11T13:55:32Z",
    "providers": [
      "Claude"
    ],
    "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify",
    "pass": 2,
    "wave": 1,
    "engine": "claude",
    "enrichment": {
      "pass": 3,
      "engine": "claude",
      "producedAt": "2026-10-05T16:30:00Z",
      "ingestedAt": "2026-10-05T13:29:56+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "owners"
      ]
    },
    "gate": {
      "passed": true,
      "version": "1.0",
      "at": "2026-10-07T10:10:33+00:00",
      "evidence": [
        "completeness 1.00",
        "sense: Wikidata description",
        "2 live sources",
        "review by codex: pass"
      ]
    }
  },
  "metaModel": {
    "id": "THING-Q920941",
    "registryId": "vr.tr.r-coronae-borealis-variable",
    "name": "R Coronae Borealis variable",
    "version": "0.2.0-wave.1",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "PHY.SPC"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q920941/",
  "model": {
    "registry_id": "vr.tr.r-coronae-borealis-variable",
    "name": "R Coronae Borealis variable",
    "purpose": "Let an agent explain R Coronae Borealis variables by properties, fading mechanism, origin models and observation data, attributing hypotheses.",
    "definition": "A rare class of hydrogen-deficient, carbon-rich supergiant stars that unpredictably fade by several magnitudes when clouds of carbon dust form near the star, then slowly recover; the prototype is R Coronae Borealis, cooler relatives are DY Persei variables, and many may result from mergers of two white dwarfs.",
    "what_it_is_for": "Stellar astrophysics and variable star observing.",
    "affordances": [
      "describe RCB star properties",
      "explain dust-formation fading",
      "summarise origin hypotheses",
      "find light curves and observing programmes"
    ],
    "distinguishing_features": [
      "Irregular deep fades",
      "Carbon dust formation",
      "Hydrogen-deficient",
      "Rare"
    ],
    "appearance": "Yellowish supergiant stars that suddenly fade and slowly return to normal brightness.",
    "visual_identification": [
      "Sudden deep fades",
      "Carbon-rich, hydrogen-poor spectra",
      "Eclipsing binaries fade periodically"
    ],
    "physical_properties": [
      {
        "quantity": "Effective temperature",
        "unit": "K",
        "typical_range": "",
        "note": "Temperature is estimated from stellar spectra and atmosphere models, with substantial variation across the class."
      },
      {
        "quantity": "Fading amplitude",
        "unit": "mag",
        "typical_range": "",
        "note": "Amplitude is measured as the difference between maximum-light and fading-event magnitudes in a specified photometric band."
      },
      {
        "quantity": "Recovery duration",
        "unit": "day",
        "typical_range": "",
        "note": "Duration is measured from a light curve using a stated criterion for return toward the pre-fading brightness."
      },
      {
        "quantity": "Hydrogen abundance",
        "unit": "dimensionless number ratio",
        "typical_range": "",
        "note": "Abundance is inferred from spectral modelling and reported relative to a specified reference element."
      }
    ],
    "families_and_kinds": [
      "classical RCB stars",
      "DY Persei variables",
      "hot RCB stars",
      "extreme helium stars (related)"
    ],
    "related_models": [
      {
        "relation": "is a kind of",
        "target": "eruptive variable star",
        "why": "category"
      },
      {
        "relation": "has example",
        "target": "R Coronae Borealis",
        "why": "prototype"
      },
      {
        "relation": "may originate from",
        "target": "white dwarf merger",
        "why": "hypothesis"
      },
      {
        "relation": "is related to",
        "target": "Beta Cephei variable",
        "why": "other variable class"
      }
    ],
    "identifiers": [
      {
        "scheme": "GCVS type",
        "value_or_pattern": "RCB",
        "note": "variable star type"
      }
    ],
    "standards_and_regulation": [
      "General Catalogue of Variable Stars classification"
    ],
    "failure_modes_and_hazards": [
      "Presenting origin hypotheses as settled",
      "Confusing fades with eclipses"
    ],
    "in_scope": [],
    "out_of_scope": [],
    "characteristics": [],
    "agent_conduct": {
      "may": [
        "Describe R Coronae Borealis variables and their fading behaviour from published data.",
        "Report brightness observations to variable star databases with their source."
      ],
      "must_not": [
        "Submit fabricated or unchecked observations to variable star databases.",
        "Misclassify a star as an R Coronae Borealis variable without evidence.",
        "Fail to credit observers whose data are used."
      ],
      "requires_human": [
        "Publishing a new classification of a star."
      ]
    },
    "ethics": {
      "considerations": [
        "Variable star science relies on volunteer observers who deserve credit and accurate records."
      ],
      "affected_parties": [
        "Amateur and professional astronomers",
        "Readers"
      ]
    },
    "owners": {
      "steward": "Nobody: natural objects held in common; astronomers catalogue them.",
      "master_systems": [
        "Variable star catalogues and observation databases"
      ]
    }
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q920941: R Coronae Borealis variable",
      "url": "https://www.wikidata.org/wiki/Q920941",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: R Coronae Borealis variable",
      "url": "https://en.wikipedia.org/wiki/R_Coronae_Borealis_variable",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "properties",
        "name": "Properties",
        "description": "What they are.",
        "rationale": "Composition is unusual.",
        "layers": [
          {
            "id": "star",
            "name": "Star",
            "description": "Stellar properties.",
            "findings": [
              {
                "id": "star-finding",
                "name": "Star",
                "description": "Stellar properties.",
                "questions": [
                  {
                    "text": "What are the temperature, luminosity and composition of this star?",
                    "kind": "measurement"
                  },
                  {
                    "text": "How is hydrogen deficiency measured?",
                    "kind": "definition"
                  }
                ]
              }
            ]
          },
          {
            "id": "class",
            "name": "Class",
            "description": "Membership.",
            "findings": [
              {
                "id": "class-finding",
                "name": "Class",
                "description": "Class membership.",
                "questions": [
                  {
                    "text": "Is the star a confirmed RCB variable or a candidate?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which catalogue lists it?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "fading",
        "name": "Fading",
        "description": "Dust events.",
        "rationale": "Dust causes fades.",
        "layers": [
          {
            "id": "mechanism",
            "name": "Mechanism",
            "description": "Carbon dust.",
            "findings": [
              {
                "id": "mechanism-finding",
                "name": "Mechanism",
                "description": "Fading mechanism.",
                "questions": [
                  {
                    "text": "How does carbon dust formation cause the fades?",
                    "kind": "definition"
                  },
                  {
                    "text": "How long do recoveries take?",
                    "kind": "measurement"
                  }
                ]
              }
            ]
          },
          {
            "id": "predict",
            "name": "Predict",
            "description": "Unpredictability.",
            "findings": [
              {
                "id": "predict-finding",
                "name": "Predict",
                "description": "Predictability.",
                "questions": [
                  {
                    "text": "Can fades be predicted?",
                    "kind": "boundary"
                  },
                  {
                    "text": "What monitoring catches them early?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "origin",
        "name": "Origin",
        "description": "Formation.",
        "rationale": "Hypotheses compete.",
        "layers": [
          {
            "id": "merger",
            "name": "Merger",
            "description": "White dwarf mergers.",
            "findings": [
              {
                "id": "merger-finding",
                "name": "Merger",
                "description": "Merger hypothesis.",
                "questions": [
                  {
                    "text": "What evidence supports the white dwarf merger origin, according to astronomers?",
                    "kind": "provenance"
                  },
                  {
                    "text": "What alternatives exist?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          },
          {
            "id": "rarity",
            "name": "Rarity",
            "description": "Numbers.",
            "findings": [
              {
                "id": "rarity-finding",
                "name": "Rarity",
                "description": "Numbers.",
                "questions": [
                  {
                    "text": "How many RCB stars are known in our galaxy and nearby galaxies?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Why are they rare?",
                    "kind": "definition"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "observing",
        "name": "Observing",
        "description": "Data.",
        "rationale": "Amateurs contribute.",
        "layers": [
          {
            "id": "data",
            "name": "Data",
            "description": "Light curves.",
            "findings": [
              {
                "id": "data-finding",
                "name": "Data",
                "description": "Light curves.",
                "questions": [
                  {
                    "text": "Where can long-term light curves of R CrB be found?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which surveys observe RCB stars?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          },
          {
            "id": "amateur",
            "name": "Amateur",
            "description": "Observing programmes.",
            "findings": [
              {
                "id": "amateur-finding",
                "name": "Amateur",
                "description": "Amateur observing.",
                "questions": [
                  {
                    "text": "How can amateurs monitor RCB stars and report fades?",
                    "kind": "action"
                  },
                  {
                    "text": "Which organisations coordinate observations?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Should each RCB star be a separate entry?",
    "How should light curve archives be linked?",
    "How should DY Persei stars be linked?"
  ],
  "statistics": {
    "bundles": 4,
    "layers": 8,
    "findings": 8,
    "questions": 16
  }
}