"α Cygni" meaning in Conventions internationales

{
  "categories": [
    {
      "kind": "other",
      "name": "Astrophysique",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Dates manquantes en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Noms propres en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Conventions internationales",
      "orig": "conventions internationales",
      "parents": [],
      "source": "w"
    }
  ],
  "derived": [
    {
      "word": "cygnien"
    },
    {
      "word": "étoile variable de type Alpha Cygni"
    }
  ],
  "etymology_texts": [
    "(Date à préciser) Du génitif latin Cygni, le préfixe α indiquant que c'est l'étoile la plus brillante de la constellation"
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "name",
  "pos_title": "Nom propre",
  "raw_tags": [
    "Alpha Cygni"
  ],
  "related": [
    {
      "word": "Alpha Cygni"
    },
    {
      "word": "Cygne"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en conventions internationales",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Étoile la plus brillante de la constellation du Cygne."
      ],
      "id": "fr-α_Cygni-conv-name-dQVwxpM4",
      "topics": [
        "astronomy"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "Déneb"
    }
  ],
  "tags": [
    "feminine"
  ],
  "word": "α Cygni"
}

{
  "categories": [
    "Astrophysique",
    "Dates manquantes en conventions internationales",
    "Noms propres en conventions internationales",
    "conventions internationales"
  ],
  "derived": [
    {
      "word": "cygnien"
    },
    {
      "word": "étoile variable de type Alpha Cygni"
    }
  ],
  "etymology_texts": [
    "(Date à préciser) Du génitif latin Cygni, le préfixe α indiquant que c'est l'étoile la plus brillante de la constellation"
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "name",
  "pos_title": "Nom propre",
  "raw_tags": [
    "Alpha Cygni"
  ],
  "related": [
    {
      "word": "Alpha Cygni"
    },
    {
      "word": "Cygne"
    }
  ],
  "senses": [
    {
      "categories": [
        "Wiktionnaire:Exemples manquants en conventions internationales"
      ],
      "glosses": [
        "Étoile la plus brillante de la constellation du Cygne."
      ],
      "topics": [
        "astronomy"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "Déneb"
    }
  ],
  "tags": [
    "feminine"
  ],
  "word": "α Cygni"
}