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Glossary term: Télescope

Description: Un télescope est un dispositif qui collecte les photons (de la lumière visible ou d'autres longueurs d'onde) d'objets éloignés et fournit des informations (par exemple une image) à leur sujet à un observateur. Les premiers télescopes (à partir du début du 17e siècle) utilisaient des lentilles comme éléments optiques (voir télescope réfractaire). Les lentilles étant limitées dans leur taille, pour voir des objets moins lumineux avec plus de détails avec des télescopes plus grands, on a utilisé des miroirs (voir télescope réflecteur) pour focaliser la lumière. Les plus grands télescopes optiques sont des télescopes à réflexion. Au XXe siècle, des télescopes permettant d'étudier d'autres régions du rayonnement électromagnétique ont été inventés. Il existe donc aujourd'hui des radiotélescopes, des télescopes infrarouges, des télescopes à rayons X, etc. Les sources célestes étant peu lumineuses, les astronomes ont tendance à construire des télescopes à grande ouverture pour collecter plus de lumière et atteindre des résolutions angulaires plus fines.

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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".

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Deux astronomes observent une éclipse lunaire. Entre eux, une série de cercles lumineux tracent une trajectoire courbe

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Caption: Beneath the sprawling expanse of the night sky over Colombia's Tatacoa Desert, a telescope finds its alignment with the majestic galactic core, while a smartphone captures this cosmic encounter. This snapshot, taken on 9 June 2023 during an astronomy camp, epitomises the accessible beauty of celestial marvels. It showcases the mesmerising grandeur of the night sky, inviting both the casual stargazer and the passionate astronomer alike. The splendour of the Milky Way, elegantly captured through a mobile device, seamlessly bridges the gap between sophisticated equipment and the pure, profound joy of observing the stars.
Credit: Juan Pablo Botero Londoño/IAU OAE (CC BY 4.0)

License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons

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