Scientists at the University of Warwick found a star that would look green. Its name is WD J1330+6435. It is a white dwarf: the small, very dense remains of a star like our Sun. Its temperature is about 4,000 degrees Celsius. The team thinks it is the first known star with a truly green colour.
White dwarfs are too far away for people to see their colours directly. The scientists measured their light. They then used a computer model of human sight to work out their colours. A star's temperature usually sets its colour. But the very dense gas around white dwarfs can change this. The green star took in bits of rock from its old system of planets. These added different materials to its gas. One material, sodium, takes in orange light. This leaves a green colour. Other white dwarfs can look pink, purple, yellow or pale blue.
The team also studied 151 nearby white dwarfs. Five had unusual colours: two yellow and three pink. They estimate that about one in 30 white dwarfs has an unusual colour. However, a typical white dwarf looks white.
