Artist interpretation of a Class Y star
Class Y stars are types of brown dwarves which are around 8 times as massive as Jupiter. These "stars" are very dim and cold, at an average surface temperature of -52 to 427ºC. Some of them are not even massive enough for deuterium fusion, which is the easiest nuclear process for stars to do and is what technically classifies an object as a star. They normally live quadrillions of years. Normally, they are just classified as big planets, and most rogue planets discovered by humans were class Y stars.
| Star Classes |
|---|
| Main Sequence
Dwarves Holes Other |