Class T Planet

Class-T planets represent the upper limits of planetary masses. Most exist within a star system's Cold Zone and are very similar to Class-S and J planets. However, Class-T planets occasionally form within a star system's Hot Zone. If they are sufficiently massive (13 times more massive than Jupiter), deuterium ignites nuclear fusion within the core, and the planet becomes a red dwarf star, creating a binary star system.

Type

Planet

Source: https://memory-gamma.fandom.com/wiki/Planetary_classification#Class-T_(Large_ultragiant)