Pluto’s family just got a little bit bigger: Astronomers have discovered a new world slightly less than 435 miles (700 kilometers) wide orbiting in the Kuiper belt, the disk of icy bodies beyond Neptune.

Provisionally dubbed 2015 RR245 by the International Astronomical Union (IAU) on July 10, the world is smaller than Pluto, Eris, Haumea, Makemake, and Ceres, the five currently recognized dwarf planets. But it’s still among the ten largest objects in the outer solar system that don’t yet have official names, according to a database curated by Caltech astronomer Mike Brown.