Gliese 393, or GJ 393, is a single star with an orbiting exoplanet companion in the equatorial constellation of Sextans, positioned about 1.5° to the NNW of Beta Sextantis. At an apparent visual magnitude of 9.65, it is much too faint to be seen with the unaided eye. This star is located at a distance of 22.9 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +8.3 km/s. It has a large proper motion, traversing the celestial sphere at the rate of per year. The net velocity of this star relative to the Sun is 32.9 km/s. It shares a similar space motion as members of the AB Doradus moving group, but is considered a random interloper.
The stellar classification of GJ 393 is M2V, indicating this is a small red dwarf star that is generating energy through core hydrogen fusion. It is rotating slowly and appears to be chromospherically inactive, suggesting it is an older star; perhaps as much as 10 billion years old. The star has 43% of the mass of the Sun and 44.6% of the Sun's radius. The metallicity, what astronomers term the abundance of heavy elements, is lower than in the Sun. It is radiating just 2.7% of the Sun's luminosity from its photosphere at an effective temperature of 3,579 K.
In 2019, one candidate planet was detected by the radial velocity method. It is classified as a hot super-Earth, with an orbital period of one week and a semimajor axis of 0.055disp=outNaNdisp=out. Longer period signals found in the data were interpreted as stellar activity.
In 2021, the planet was confirmed as real after being detected independently in three different datasets.