Astronomers at the University of Sydney have shown that a small, faint star is the coldest on record to produce emission at radio wavelength.

The ‘ultracool brown dwarf’ examined in the study is a ball of gas simmering at about 425 degrees centigrade—cooler than a typical campfire—without burning nuclear fuel.

By contrast, the surface temperature of the sun, a nuclear inferno, is about 5,600 degrees.