Z

T-type:

Class T dwarfs are cool brown dwarfs with surface temperatures between approximately 550 and 1,300 K (277 and 1,027 °C; 530 and 1,880 °F). Their emission peaks in the infrared. Methane is prominent in their spectra. Classes T and L could be more common than all the other classes combined if recent research is accurate. Because brown dwarfs persist for so long—a few times the age of the universe—in the absence of catastrophic collisions these smaller bodies can only increase in number.