Traduit par IA (Opus 5.5) à partir de la fiche anglaise. Les nombres, noms et sources sont inchangés.

Étoile avec 6 planètes connues

K2-138

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K2-138, une étoile G8 V, possède 6 planètes confirmées.

Mesuré

Distance: environ 661 années-lumière
Type spectral de l'étoile: G8 V
Planètes confirmées: 6

Distance au Soleil

À propos 661 années-lumière. Pour la traverser :

Lumière661 ans
Vitesse de Voyager 111.7 millions d’années
Roule à 100 km/h7.13 milliards d'années

Voyager 1 à la vitesse à laquelle elle s'est éloignée au cours de l'année jusqu'à 2026-10-25 (JPL Horizons). En voiture : sans arrêt, sans jamais refaire le plein.

Méthode de découverte

Première planète découverte en 2017, par transit (NASA Exoplanet Archive).

Ses planètes

K2-138 c — 2.3 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 4 days; about 740 °C, hotter than boiling water; found in 2017 by transit.
K2-138 d — 2.4 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 5 days; about 620 °C, hotter than boiling water; found in 2017 by transit.
K2-138 b — 1.5 times Earth's width, about Earth-sized — probably rocky; its year lasts 2 days; about 880 °C, hotter than boiling water; found in 2017 by transit.
K2-138 e — 3.4 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 8 days; about 480 °C, hotter than boiling water; found in 2017 by transit.
K2-138 g — 3 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 42 days; about 170 °C, hotter than boiling water; found in 2021 by transit.
K2-138 f — 2.9 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 13 days; about 380 °C, hotter than boiling water; found in 2017 by transit.

The NASA Exoplanet Archive's page

Source

NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.
This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.

Chaque catalogue utilisé par Ouranos est cité dans la page des crédits.

Distance au Soleil

À propos 661 années-lumière. Pour la traverser :

Lumière661 ans

Vitesse de Voyager 111.7 millions d’années

Roule à 100 km/h7.13 milliards d'années

Voyager 1 à la vitesse à laquelle elle s'est éloignée au cours de l'année jusqu'à 2026-10-25 (JPL Horizons). En voiture : sans arrêt, sans jamais refaire le plein.

Ses planètes

K2-138 c — 2.3 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 4 days; about 740 °C, hotter than boiling water; found in 2017 by transit.

K2-138 d — 2.4 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 5 days; about 620 °C, hotter than boiling water; found in 2017 by transit.

K2-138 b — 1.5 times Earth's width, about Earth-sized — probably rocky; its year lasts 2 days; about 880 °C, hotter than boiling water; found in 2017 by transit.

K2-138 e — 3.4 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 8 days; about 480 °C, hotter than boiling water; found in 2017 by transit.

K2-138 g — 3 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 42 days; about 170 °C, hotter than boiling water; found in 2021 by transit.

K2-138 f — 2.9 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 13 days; about 380 °C, hotter than boiling water; found in 2017 by transit.

Source

NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.

This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.