Proxima Cen

M5.5 V型星のプロキシマ・ケンタウリには、確認済みの惑星が2個あります。

測定値

概要 4.2光年. 横断するには:

2026-10-25までの1年間に外向きに進んだ速さでのボイジャー1号（JPL Horizons）。走行条件：休みなし、給油なし。

Proxima Cen b — 1 times Earth's width (estimated from its mass, not measured), about Earth-sized — probably rocky; its year lasts 11 days; about −55 °C, below freezing; found in 2016 by radial velocity.
Proxima Cen d — 0.7 times Earth's width (estimated from its mass, not measured), smaller than the Earth; its year lasts 5 days; about 9 °C, between freezing and boiling; found in 2025 by radial velocity.

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.

英語版カードからAI（Opus 5.5）により翻訳。数値、名称、出典は変更していません。

2個の惑星が知られている恒星

M5.5 V型星のプロキシマ・ケンタウリには、確認済みの惑星が2個あります。

概要 4.2光年. 横断するには:

2026-10-25までの1年間に外向きに進んだ速さでのボイジャー1号（JPL Horizons）。走行条件：休みなし、給油なし。

Proxima Cen b — 1 times Earth's width (estimated from its mass, not measured), about Earth-sized — probably rocky; its year lasts 11 days; about −55 °C, below freezing; found in 2016 by radial velocity.
Proxima Cen d — 0.7 times Earth's width (estimated from its mass, not measured), smaller than the Earth; its year lasts 5 days; about 9 °C, between freezing and boiling; found in 2025 by radial velocity.

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.