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Glossary term: Exoplanète

Description: Une exoplanète, ou planète extrasolaire, est une planète située en dehors du système solaire. Leur existence a été théorisée dès le XVIe siècle et la recherche observationnelle a commencé au XIXe siècle pour les trouver. Les premières exoplanètes confirmées ont été découvertes dans les années 1990. Parmi celles-ci, la première exoplanète confirmée en orbite autour d'une étoile de la séquence principale est l'exoplanète Dimidium, découverte indirectement à l'Observatoire de Haute-Provence. Cette exoplanète est en orbite autour de l'étoile 51 Pegasi, une sous-géante jaune, et a été découverte en 1995. Depuis, des milliers d'exoplanètes ont été identifiées.

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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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Related Media


La planète Beta Pictoris b est un point lumineux proche de son étoile mère. Autour de cela, nous voyons un disque chaud vu par la tranche

beta Pictoris b

Caption: Ce composite de deux images montre la planète beta Pictoris b et un disque de matière, tous deux en orbite autour de la jeune étoile beta Pictoris. Les deux images sont prises en lumière infrarouge. L'image intérieure est l'une des premières images prises d'une planète autour d'une autre étoile (une exoplanète). Cette image a été réalisée à l'aide d'une technique appelée optique adaptative qui supprime l'effet de flou de l'atmosphère terrestre qui étale la lumière d'une étoile. La lumière de l'étoile est alors suffisamment concentrée pour être cachée derrière un cercle de blocage (ici en noir) appelé coronographe. Les ondulations autour de ce cercle sont des artefacts du processus d'imagerie. Beta Pictoris b, une planète géante gazeuse dont la masse est environ douze fois supérieure à celle de Jupiter, apparaît comme un point au-dessus et à gauche du cercle noir. L'image extérieure montre l'émission thermique du disque de matière chaude entourant la jeune étoile Beta Pictoris. par la tranche, il apparaît sous forme d'une ligne. Ce disque de gaz et de poussière a fourni la matière nécessaire à la formation de beta Pictoris b.
Credit: ESO/A.-M. Lagrange et al. credit link

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


beta Pictoris b moves from bottom right towards the center of the image, reappearing 22 months later on the top left

The orbit of beta Pictoris b

Caption: This series of images shows the orbital motion of the extrasolar planet (exoplanet) beta Pictoris b. The planet is the bright dot in each image. The planet's host star is hidden behind the black circle in the middle of each image. This is done to remove the much brighter host star which would otherwise drown out the light from the planet. The planet's orbit is viewed edge-on. Seeing the orbit from this perspective makes it look like the planet moves along a straight line. Between February 2015 and November 2016 beta Pictoris b appears to move closer and closer to its host star. The planet then moved so close to the star that it was not seen for almost two years, after which it reappeared on the other side of the star.
Credit: ESO/Lagrange/SPHERE consortium credit link

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

Related Diagrams


Pictor appears as a slightly bent line going from the south east to north west

Pictor Constellation Map

Caption: The constellation Pictor with its bright stars and surrounding constellations. Pictor is surrounded by (going clockwise from the top): Columba, Caelum, Dorado, Volans, Carina and Puppis. Pictor is notable for its second brightest star, Beta Pictoris. This young star hosts a large disk of dusty material left over from the planet formation process along with two planets, one of which Beta Pictoris b was one of the first planets to be directly imaged by astronomers. Pictor is a southern constellation and thus the whole constellation is visible at some point in the year throughout the southern hemisphere. The whole constellation is also visible from some equatorial regions of the northern hemisphere with parts of the constellation visible to the remaining northern equatorial regions and some northern hemisphere temperate zones. Pictor is best viewed in the northern hemisphere winter and southern hemisphere summer. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

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

Related Activities


Can you find the exoplanet?

Can you find the exoplanet?

astroEDU educational activity (links to astroEDU website)
Description: Find the exoplanet and determine its size using data from the Spitzer Space Telescope!

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

Age Ranges: 14-16 , 16-19
Education Level: Secondary
Areas of Learning: Guided-discovery learning , Modelling , Observation based , Problem-solving , Social Research , Technology-based
Costs: Free
Duration: 3 hours
Skills: Analysing and interpreting data , Asking questions , Using mathematics and computational thinking

Measuring an exoplanet

Measuring an exoplanet

astroEDU educational activity (links to astroEDU website)
Description: Let's learn about exoplanets and how to measure their size!

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

Age Ranges: 12-14 , 14-16
Education Level: Middle School , Secondary
Areas of Learning: Observation based , Problem-solving
Costs: Free
Duration: 2 hours
Group Size: Group
Skills: Analysing and interpreting data , Developing and using models , Using mathematics and computational thinking

Exoplanet in a box

Exoplanet in a box

astroEDU educational activity (links to astroEDU website)
Description: Build a "transit simulator" in a box using some very simple material and your cell phone!

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

Age Ranges: 14-16 , 16-19
Education Level: Secondary , University
Areas of Learning: Modelling , Observation based , Project-based learning , Social Research , Technology-based
Costs: Low Cost
Duration: 3-6 hours
Group Size: Group
Skills: Analysing and interpreting data , Asking questions , Developing and using models , Planning and carrying out investigations