About this world
TOI-1266 d is a super-Earth orbiting TOI-1266, a cool red dwarf (type M2) 117 light-years from Earth. It is about 1.7 times the size of Earth (its size estimated from its mass) and holds 3.7 Earth masses. It completes an orbit every 32.5 days at 0.15 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 288 K (15 °C), which places it in the optimistic habitable zone: the band where liquid water could exist on a rocky surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
It was discovered in 2025 by timing variations with Transiting Exoplanet Survey Satellite (TESS). Pulsar, eclipse or transit timings drift as an unseen companion tugs on them. TOI-1266 has 3 known planets; the others are TOI-1266 b and TOI-1266 c.