In a first, astronomers have identified a green star a white dwarf called WD J1330+6435 located about 326 light-years from Earth. The researchers found that some dead star white dwarfs can go a little green around the gills after snacking on orbiting planets, according to Space.com. The strange cosmic object 'Green Star' has earned the nickname “zombie star” because of its unusual afterlife. The object is a white dwarf, the dense remnant left behind after a star like the Sun exhausts its nuclear fuel.
WD J1330+6435, a cool white dwarf located around 326 light-years away, which has been accreting rocky material from a planetary companion. This has enriched its atmosphere with calcium, lithium, and sodium, and the team's model suggests this would have led WD J1330+6435 to adopt a green hue.
The findings, published in the journal RAS Techniques and Instruments in October 2026, suggest that the remains of stars may display a much wider range of colours than astronomers traditionally expected.
"We first became interested in this white dwarf because bits of planetary material have fallen onto its surface, enriching its outer layers in elements including calcium, lithium and, in particular, sodium," said astrophysicist Mark Hollands of the University of Warwick in England, lead author of the study published in the journal RAS Techniques and Instruments, reports Reuters.
In normal stars, sodium absorbs a very specific wavelength of orange. But in green star, the density is so high that the sodium atoms are constantly being bombarded by surrounding helium atoms, which alters the sodium atomic energy levels, Hollands explained.
"The end result is that the sodium atoms no longer absorb one very narrow wavelength of orange — they absorb the yellows, oranges and some of the red wavelengths. And what you're left with is a star that has a beautiful chartreuse green glow, something that wouldn't be possible for sun-like stars," Hollands said.
Why is the green star being called a ‘zombie’?
The researchers think that no other star, living or dead, has ever been credibly reported as green. That makes WD J1330+6435 the first known genuinely green star. "The traces of sodium in the atmosphere of this white dwarf absorb the orange part of the spectrum, leaving behind a ghostly green glow," Hollands told CNN. "Imagine standing on a planet and looking up at a green star. It feels like something out of science fiction."
WD J1330+6435 is a white dwarf, the dense remnant left behind after a star dies. It has been absorbing rocky material from its planetary surroundings, enriching its atmosphere with elements such as calcium, lithium and sodium. This ongoing process has earned it the nickname “zombie star”.
White dwarf star with a 'ghostly green glow'. A study finds that some them may appear colorful to human eyes. (Illustrative image courtesy: University of Warwick)
“The colors that normal stars can have are pretty much only orange, white or blue,” Mark Hollands, an astrophysicist at the University of Warwick in England and lead author of the study, told CNN. He explained that the unusual green appearance of WD J1330+6435 is linked to the physical conditions in its atmosphere, which alter the wavelengths of light absorbed by the star. The green appearance of WD J1330+6435 is linked to the behaviour of sodium in the white dwarf’s extremely dense atmosphere.
Could the Sun turn into a green star?
The Sun is expected to become a white dwarf billions of years from now. However, it will not necessarily turn green. Its eventual colour would depend on its atmospheric composition and surrounding conditions. The discovery offers astronomers new insights into what happens to stars and their planetary systems after stellar death.