Le télescope James Webb découvre une géante gazeuse tempérée contenant du méthane

22 mai 2026

Rapporté par l'IA

Des astronomes utilisant le télescope spatial James Webb de la NASA ont étudié l'atmosphère de TOI-199b, une planète rare de la taille de Saturne dont la température avoisine les 80 degrés Celsius. Ces résultats constituent le premier examen détaillé d'une exoplanète géante tempérée.

La planète orbite autour d'une étoile située à plus de 330 années-lumière de la Terre et effectue une révolution complète tous les 100 jours. Les chercheurs ont détecté du méthane dans son atmosphère à l'aide de la spectroscopie de transmission lors d'un transit de sept heures, observé sur une période totale de 20 heures.

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mardi 12 mai 2026 22h40