Associate Professor Kevin Luhman of Penn State University has discovered the coldest brown dwarf yet using the NASA’s Wide-field Infrared Survey Explorer.
A brown dwarf is a massive gaseous object which is on the low end of the stellar mass and temperature scale. There’s an heated (pardon the pun) debate regarding the classifications of brown dwarfs. They are not truly stars since they lack a prolonged hydrogen fusion system but they have a typically stellar chemical composition and are in general more massive than your average giant planet.
The new object has a temperature between 235-260 K (-38 to -13 °C), it is located 7.2 light years away from the Solar System and it has a mass between 3 and 10 times the mass of Jupiter. This make it not only the coldest brown dwarf discovered but possibly the lightest. These characteristics are puzzling scientists. Is this object a true brown dwarf or is it a rough planet escaped from its star-system after its formation?