GJ 9404 b: A Nearby Planet Around a Small Red Dwarf

GJ 9404 is a single M2V star, an M-type dwarf and thus a small, cool red dwarf, located 77.9 light-years away. Its spectral type places it among the cooler, redder stars. The star is measured at 0.55 solar masses, 0.73 solar radii, and 3810 K, making it less massive, smaller, and cooler than the Sun. One planet is known to orbit this host.

That planet is GJ 9404 b, discovered in 2023 by the radial velocity method, which detects the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period. GJ 9404 b has a minimum mass of 11.9 Earth masses, a lower bound on its true mass, and it is more massive than Earth on that measure. It completes one orbit every 13.5 days.