# Fame.am profile — machine-readable export
# Canonical URL: https://fame.am/person/cornelis-de-jager
# Generated: 2026-08-13T23:24:23.068Z

schema: https://schema.org/Person
url: "https://fame.am/person/cornelis-de-jager"
name: "Cornelis de Jager"
slug: "cornelis-de-jager"
description: "Cornelis \"Kees\" de Jager was a Dutch astronomer who specialized in predicting solar variation to assess the Sun's impact on future climate. He was the General Secretary of the IAU from 1967 to 1973 and former director of the observatory at Utrecht. He was a fellow with the Committee for Skeptical Inquiry and played an important role in the European skeptical movement as the first chairman of both Stichting Skepsis and the European Council of Skeptical Organisations."
tagline: "Dutch astronomer, university professor, pioneer of space science, science communicator and opponent of pseudoscience (1921–2021)"
image: "https://commons.wikimedia.org/wiki/Special:FilePath/Kees-de-jager-1967.jpg?width=1200"
gender: "male"
category:
  name: "Scientists"
  slug: "scientists"
profileType:
  name: "Scientist"
  slug: "scientist"
  entityType: "https://www.wikidata.org/entity/Q39631"
birthDate: "1921-04-29"
deathDate: "2021-05-27"
livingStatus: "DECEASED"
scores:
  popularity:           49.06
  momentum:             12
  historical:           14.419116
  currentAttention:     0
  sourceConfidence:     65
  profileCompleteness:  65
  trendDirection:       "RISING"
ranks:
  global:   null
  country:  null
  category: null
platforms:
  - platform:  "WEBSITE"
    url:       "https://web.archive.org/web/20210803050944if_/http://www.cdejager.com/"
sources:
  - url: "https://zh.wikipedia.org/wiki/%E7%A7%91%E5%86%85%E5%88%A9%E6%96%AF%C2%B7%E5%BE%B7%E4%BA%9A%E8%B5%AB"
    title: "科内利斯·德亚赫"
    type:  "WIKIPEDIA"
  - url: "https://ar.wikipedia.org/wiki/%D9%83%D9%88%D8%B1%D9%86%D9%8A%D9%84%D9%8A%D8%B3_%D8%AF%D9%8A_%D9%8A%D8%A7%D8%AC%D8%B1"
    title: "كورنيليس دي ياجر"
    type:  "WIKIPEDIA"
  - url: "https://arz.wikipedia.org/wiki/%D9%83%D9%88%D8%B1%D9%86%D9%8A%D9%84%D9%8A%D8%B3_%D8%AF%D9%89_%D8%AC%D8%A7%D8%AC%D8%B1"
    title: "كورنيليس دى جاجر"
    type:  "WIKIPEDIA"
  - url: "https://ca.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://de.wikipedia.org/wiki/Cornelis_de_Jager"
    title: "Cornelis de Jager"
    type:  "WIKIPEDIA"
  - url: "https://en.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://eo.wikipedia.org/wiki/Cornelis_de_Jager"
    title: "Cornelis de Jager"
    type:  "WIKIPEDIA"
  - url: "https://es.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://fi.wikipedia.org/wiki/Cornelis_de_Jager"
    title: "Cornelis de Jager"
    type:  "WIKIPEDIA"
  - url: "https://fr.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://ja.wikipedia.org/wiki/%E3%82%B3%E3%83%AB%E3%83%8D%E3%83%AA%E3%82%B9%E3%83%BB%E3%83%87%E3%83%BB%E3%83%A4%E3%83%98%E3%83%AB"
    title: "コルネリス・デ・ヤヘル"
    type:  "WIKIPEDIA"
  - url: "https://nl.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://pt.wikipedia.org/wiki/Cornelis_de_Jager"
    title: "Cornelis de Jager"
    type:  "WIKIPEDIA"
  - url: "https://ru.wikipedia.org/wiki/%D0%94%D0%B5_%D0%AF%D0%B3%D0%B5%D1%80%2C_%D0%9A%D0%BE%D1%80%D0%BD%D0%B5%D0%BB%D0%B8%D1%81"
    title: "Де Ягер, Корнелис"
    type:  "WIKIPEDIA"
  - url: "https://simple.wikipedia.org/wiki/Kees_de_Jager"
    title: "Kees de Jager"
    type:  "WIKIPEDIA"
  - url: "https://sv.wikipedia.org/wiki/Cornelis_de_Jager"
    title: "Cornelis de Jager"
    type:  "WIKIPEDIA"
  - url: "https://uk.wikipedia.org/wiki/%D0%9A%D0%BE%D1%80%D0%BD%D0%B5%D0%BB%D1%96%D1%81_%D0%B4%D0%B5_%D0%AF%D0%B3%D0%B5%D1%80"
    title: "Корнеліс де Ягер"
    type:  "WIKIPEDIA"
  - url: "https://www.wikidata.org/wiki/Q1133624"
    title: "Wikidata"
    type:  "WIKIDATA"

# bio (long form, separated for readability)
bio: |
  Imported from discovery source: wikidata-dump