ZTF J1239+8347

Summary

ZTF J1239+8347 is a binary system of brown dwarfs orbiting extremely close to each other with an orbital period of 57.41 minutes. It is located in the constellation Cepheus, about 1,110 light-years (339 pc) away from Earth. The system was first identified in various studies of the Gaia catalogues from 2018 to 2024, but it was not recognized as a binary brown dwarf until 2026.