TOI-1136



TOI-1136 is a G-type main-sequence star 276 ly away in the constellation Draco. It is slightly smaller than the Sun and similar in mass and temperature, but is much younger, with an age of about 700 million years. It hosts a system of at least six, and possibly seven, exoplanets.

Planetary system
TOI-1136 was discovered to have six transiting planets in 2022 using the Transiting Exoplanet Survey Satellite (TESS), all orbiting closer to their star than Mercury is to the Sun. All of them are Neptune-sized or mini-Neptunes, and their masses have been measured using a combination of radial velocity and transit-timing variations, showing them to have low densities. The planets are in an orbital resonance, with period ratios near 3:2, 2:1, 3:2, 7:5, and 3:2.

A possible single transit of a seventh planet was also identified. This candidate planet would also be sub-Neptune-sized, but its orbit is poorly constrained. If this is confirmed, it would make TOI-1136 one of the largest known planetary systems.