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A bright oval with a dark circle in the center. To the right of the dark circle but still inside the oval is a bright dot.

The planet PDS 70b inside a protoplanetary disk

image

Légende : An image of the planet PDS 70b. The young star PDS 70b has a protoplanetary disk surrounding it. Disks like these contains gas, fine sandy particles that astronomers refer to as dust and also larger bodies ranging from objects the size of pebbles to protoplanets (planets that are still forming). This image was taken in infrared light using adaptive optics. Adaptive optics is a technique that uses flexible mirrors and computer analysis to remove the blurring effect of the Earth's atmosphere. This allows astronomers to search regions close to stars like PDS 70 that would otherwise be swamped by light from the star spread out by the Earth's atmosphere. In the center is a black circle. This is caused by a coronograph, a small circle that blocks out light from the parent star. This is surrounded by a bright oval, infrared light emitted from the material in the protoplanetary disk. To the right of the black circle covering the star is a bright dot. This is PDS 70b, a giant planet that is still forming .
Crédit : ESO/ A. Müller, MPIA
Lien du crédit

Termes du glossaire: Formation de planètes , Protoplanète , Disque protoplanétaire , Optique adaptative
Catégories : Exoplanètes et astrobiologie

Licence : Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Icônes

Fichier ( image 1.59 MB)


A red patch mass of gas with a few dark bubbles with lighter edges and several lighter colored clusters and filaments

Herschel’s view of new stars and molecular clouds

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Légende : This image shows the Westerhout 3, 4 and 5 star formation regions. This area has huge amounts of gas and dust. This gas and dust hides the physical processes going on in this region from studies using visible light. This image was taken in infrared light by the Herschel Space Observatory. This infrared light allowed Herschel to see deep into these star forming regions. In Westerhout 3, 4 and 5, huge, cold clouds of molecular hydrogen have collapsed into dense knots and filaments. Within these new structures the gas is dense and cold enough for it to collapse and form stars. These new stars give off powerful winds of charged particles, like stronger versions of the solar wind our sun gives off. These winds have combined to blow massive bubbles in the surrounding gas and dust. These are visible as the large darker voids in the image.
Crédit : ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech)
Lien du crédit

Termes du glossaire: Astronomie infrarouge , Formation des étoiles , Milieu interstellaire , Nuage moléculaire , Vent stellaire
Catégories : Voie lactée et milieu interstellaire , Étoiles

Licence : Creative Commons (CC) Attribution 3.0 Organisations Internationales Creative Commons (CC) Attribution 3.0 Organisations Internationales Icônes

Fichier ( image 4.53 MB)


Young stars form along a ribbon of gas

Stellar birth environment

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Légende : Snapshot of the formation of multiple protostars in the Orion Molecular Clouds with a closer look at each of them with the Atacama Large Millimeter/submillimeter Array and Very Large Array. Such an image provides unique insights of the process and early stages of star formation as well as the influence of the parent cloud in which they form.
Crédit : ALMA (ESO/NAOJ/NRAO), J. Tobin; NRAO/AUI/NSF, S. Dagnello; Herschel/ESA
Lien du crédit

Termes du glossaire: Protoétoile , Formation des étoiles
Catégories : Voie lactée et milieu interstellaire , Étoiles

Licence : Creative Commons (CC) Attribution 3.0 non transposé Creative Commons (CC) Attribution 3.0 non transposé Icônes

Fichier ( image 426.34 kB)


A series of light and dark rings that resemble an archery target around the star TW Hydrae

Planet formation around the star TW Hydrae

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Légende : This image shows the disk around the young star TW Hydrae. This star is only about 10 million years old, young enough that planets are still forming in a disk of gas and dust around it. This image was created using an array of submillimetre telescopes, each of which looks like a satellite dish. The signals from these telescopes were combined by a central processing computer to make this image. The lighter and darker patches show areas of the disk where there is more or less dust respectively. The dark rings and bright rings are evidence that the dust in the disk has been shepherded into some orbits and away from others. This is likely because there is one or more planets that are still forming hidden in the disk. The whole image shows the disk around TW Hydrae out to a distance of about 70 astronomical units frm the central star. The two outer dark rings are separated from the central star by approximately the average distance between the Sun and Uranus and the average distance between the Sun and Pluto. The inner central hole appears to have been carved out by a planet orbiting TW Hydrae at a distance similar to the distance between the Earth and the Sun.
Crédit : S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)
Lien du crédit

Termes du glossaire: Formation de planètes
Catégories : Exoplanètes et astrobiologie

Licence : Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Icônes

Fichier ( image 210.48 kB)


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

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Légende : 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.
Crédit : ESO/A.-M. Lagrange et al.
Lien du crédit

Termes du glossaire: Exoplanète , Formation de planètes , Optique adaptative
Catégories : Exoplanètes et astrobiologie

Licence : Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Creative Commons (CC) Attribution 4.0 International (CC BY 4.0) Icônes

Fichier ( image 128.05 kB)


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