A quiet red dwarf with two habitable-zone Earths

TOI-700

Four worlds around a small, calm M dwarf: a rocky pair, a sub-Neptune, and two Earth-sized planets in the temperate zone. Hover for a quick look, or select a planet for its field notes.

TOI-700 An unusually quiet red dwarf, distant enough for TESS to have found its small planets. Type M2.5V red dwarf Distance 101.5 light-years Mass About 0.42 Suns Temperature About 3,480 K TOI-700 b Confirmed A hot, Earth-sized world hugging the star. Solar Distance 0.0677 AU · 10.1 million km Size and Gravity 0.91 Earth radii · mass unknown Atmosphere and Weather Unknown; no atmosphere detected Moons and Satellites None known Day and Year 9.98-day orbit; rotation unknown Surface Temperature Estimated around 400 K Habitability Verdict Too hot for surface liquid water TOI-700 c Confirmed A sub-Neptune: too large and gas-wrapped to be an Earth twin. Solar Distance 0.0929 AU · 13.9 million km Size and Gravity 2.60 Earth radii · mass unknown Atmosphere and Weather Likely a thick hydrogen-rich envelope Moons and Satellites None known Day and Year 16.05-day orbit; rotation unknown Surface Temperature Estimated around 356 K Habitability Verdict No solid surface; not considered habitable TOI-700 e Confirmed A second Earth-sized world, inside the habitable zone between c and d. Solar Distance 0.134 AU · 20.1 million km Size and Gravity 0.95 Earth radii · mass unknown Atmosphere and Weather Unknown; no atmosphere detected Moons and Satellites None known Day and Year 27.8-day orbit; rotation unknown Surface Temperature Estimated around 273 K Habitability Verdict Inside the habitable zone; surface conditions unknown TOI-700 d Confirmed The first Earth-sized world found by TESS inside a habitable zone. Solar Distance 0.163 AU · 24.4 million km Size and Gravity 1.07 Earth radii · mass unknown Atmosphere and Weather Unknown; no atmosphere detected Moons and Satellites None known Day and Year 37.4-day orbit; rotation unknown Surface Temperature Estimated around 268 K Habitability Verdict Inside the habitable zone; surface conditions unknown

A quiet M dwarf · two Earth-sized habitable-zone planets · one sub-Neptune · one hot rock

Orbit spacing and animation are illustrative, not to scale. Orbital periods are shown in the planet notes.

Planet data: NASA Exoplanet Archive · NASA TOI-700 catalog · Gilbert et al. 2020