A four-stage sequence (left to right) showing the possible extreme temperature evolution for WISE J0304-2705. When young, the object was as hot as a star, shining with a temperature of at least 5,100° F (2,800° C) for about 20 million years. After 100 million years or so, it had cooled to 2,700° F (1,500° C), and by a billion years its temperature was around 1,800° F (1,000° C). The final stage is billions of years later, when WISE J0304-2705 had cooled to its current planetary temperature of 210°–300° F (100°–150° C).
John Pinfield, 2014