object

red dwarf planets

Planets orbiting red dwarf stars, often with short orbital periods.
87 related articles

Description

Red dwarf stars are the most common stars in the galaxy, and their planets are prime targets for exoplanet searches. These planets often orbit very close to their dim, cool parent stars, resulting in short orbital periods of days or even hours. Because the habitable zone around a red dwarf is so close, planets there are frequently tidally locked, with one hemisphere permanently facing the star and the other in eternal darkness. This creates extreme temperature contrasts and unique atmospheric circulation patterns.

History

The first confirmed exoplanet around a red dwarf, Gliese 876 b, was discovered in 1998 by a team led by Geoffrey Marcy and Paul Butler. Since then, surveys like MEarth and TRAPPIST have revealed many more, including the famous TRAPPIST-1 system with seven Earth-sized planets.

How it works

Red dwarfs are small and faint, so their gravitational pull is weaker than that of Sun-like stars, allowing planets to orbit very close without being destroyed. The close orbit means the planet's year is short, and tidal forces from the star can cause significant internal heating, a process called tidal dissipation. This heating can melt planetary interiors, drive volcanic activity, and even sustain subsurface oceans, as seen in some of the most intriguing exoplanet models.

In practice

Red dwarf planets are the primary targets for upcoming missions like the James Webb Space Telescope, which will analyze their atmospheres for biosignatures, and they are also studied to understand tidal heating and orbital dynamics in extreme environments.

Fun fact

Because red dwarfs are so dim, a planet in their habitable zone would have its star appearing as a large, glowing red disk in the sky, and the planet would be in perpetual twilight on its day side.

Concept graph →

Related articles · 87

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X-ray passports for habitable worlds
Twelve stars have received X-ray passports. Now, for each of them, we know the exact radiation dose received by a planet in the habitable zone, the region where liquid water is possible.
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Rare Guests in Poor Outskirts: Where Supernovae 2003fg Explode
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Galaxies2026-08-182 minarXiv:2608.17375express
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Exoplanets2026-08-161 minarXiv:2608.15912express
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Stellar2026-08-072 minarXiv:2608.07331express
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Stellar2026-08-072 minarXiv:2608.07455express
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Plasma Physics2026-08-031 minarXiv:2608.02418express
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A Symmetric Shadow in the Chaos of Tabby's Star
Tabby's Star, a beacon in the cosmic sea, has baffled astronomers since 2015. Its light flickered not in the rhythm of planets, but as if scattered by a storm — deep dips, sharp spikes. But amid this chaos, a smooth, nearly perfect dip was found. The eye of the storm.
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In deep space, 95 parsecs from Earth, nature is assembling a planetary clock. The model HD 114082 is a prototype, only 15 million years old. Two massive pendulums — exoplanets b and c — are already swinging with periods of 225 and 314 days, but the whole mechanism is still covered in the construction dust of a debris disk.
Cosmic Carving: Birth of a Bloated Neptune from a Jupiter
A ball, almost weightless for its size, circles its star every four days. Planet TOI-2195 A b is a real riddle: by mass it's slightly heavier than Neptune, yet bloated to Jovian volumes. If there were an ocean big enough, this exoplanet would float on its surface like a giant inflatable ball.
Galaxies2026-06-234 minarXiv:2606.25214
Echo of Millions of Suns: Fast Radio Bursts Reveal Galaxy History
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James Webb Fishes Out an Invisible Planet from a Dusty Disk
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A planet the size of Neptune wandered too close to its star. The star begins to pull the planet's outer layers onto itself — gas streams off the planet like water from an overflowing bucket. This process is called Roche-lobe overflow (astronomers use this term for the boundary beyond which a star can tear material away from a planet).
The Cosmic Forge: Why GJ 3929 b Lost Its Air
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In the constellation Scorpius, 3,000 light-years from Earth, a dead star steals matter from a living one. A white dwarf in the system IGR J17014-4306 — a superdense carbon-oxygen ball with the mass of the Sun but the size of Earth — siphons hydrogen from a normal companion star.
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General Relativity2026-05-142 minarXiv:2605.14728express
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High Energy2026-05-131 minarXiv:2605.14077express
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The first exoplanet was discovered around an unusual cosmic lighthouse — a neutron star known as a pulsar. These ultra-dense remnants of dead stars spin at tremendous speeds and emit precise radio pulses.
Exoplanets2026-04-251 minarXiv:2604.23448express
Giant Planet or Twin World?
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Galaxies2026-04-242 minarXiv:2604.22702express
More Than a Hundred Distant Stars in a Single Galaxy
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Exoplanets2026-04-221 minarXiv:2604.20325express
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Exoplanets2026-04-211 minarXiv:2604.19179express
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Stellar2026-04-131 minarXiv:2604.11955express