Astronomers from the University of Sydney have presented a unique description of an ultra-cold brown dwarf, which is the coldest radio-emitting star ever detected using radio astronomy. This star, dubbed T8 Dwarf WISE J062309.94-045624.6, is a ball of gas with a temperature of only about 425 degrees Celsius. By comparison, the temperature at the surface of the Sun reaches 5,600 degrees Celsius. However, despite its low temperature, this star emits radio waves and is about 37 light-years away from Earth.
Brown dwarfs are special objects in the universe. They are not massive enough to trigger nuclear fusion like our Sun does. Instead, they are balls of gas composed mostly of hydrogen and helium. Brown dwarfs are a kind of missing link between the smallest stars that burn hydrogen in nuclear reactions and the largest gas giant planets like Jupiter.
It is very rare to find an ultracold brown dwarf producing radio emission. Usually their dynamics do not create the magnetic fields that generate the radio emission observed from Earth. Therefore, finding a brown dwarf emitting radio waves at such a low temperature is an excellent discovery.
Scientists continue to study this unique star and its properties. However, they already suggest that the mass of T8 Dwarf WISE J062309.94-045624.6 could be between four and 44 times the mass of Jupiter. By comparison, the Sun is 1,000 times more massive than Jupiter.
This discovery is of great importance to astronomy and increases our knowledge of stars and their diversity. Ultra-cold brown dwarfs are objects that are not yet fully understood, and each new discovery in this field brings new data and opportunities to explore the universe.