Astronomers Find the First Green Star, and It's a Dead One
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Ask any astronomy teacher whether green stars exist and you will hear a firm no. Stars come in red, orange, yellow, white and blue, but never green. In October 2026, researchers at the University of Warwick found an exception: a dead star that would look genuinely green to human eyes, widely reported as the first green star ever identified.
Why stars are almost never green
A normal star's color comes mostly from its temperature. Cooler stars give off more red light; hotter stars give off more blue. But every star emits a broad mix of wavelengths.
Even a star whose light peaks in the green part of the spectrum, like our Sun, also pours out plenty of red and blue. Our eyes blend all of that together, so the Sun and similar stars look white or yellowish, never green. Physicists call this behavior being a near-perfect radiator.
Where white dwarfs break the rule
White dwarfs are the dense, Earth-sized cores left behind when Sun-like stars run out of fuel and shed their outer layers. Their atmospheres are extremely thin and dense at the same time, and they are often mostly helium.
In that strange environment, traces of other elements can change the light dramatically. If those elements absorb large chunks of the spectrum, the color that escapes is no longer the simple product of temperature.
Meet WD J1330+6435, the green one
The green white dwarf, catalogued as WD J1330+6435, lies about 280 light-years from Earth and has a surface temperature of roughly 4,000 °C. Its helium atmosphere contains sodium, calcium and lithium.
In an ordinary star, sodium absorbs only a narrow sliver of orange light. In this white dwarf, constant collisions with helium atoms make sodium absorb a much wider band, eating up yellow, orange and some red. What survives leans green.
Where did the sodium come from? The leading explanation is rocky debris from the star's own former planetary system. Asteroids or broken planets that wander too close get shredded, and the dust rains onto the white dwarf.
A whole rainbow of dead stars
The study, led by astrophysicist Mark Hollands and published in RAS Techniques and Instruments, examined 151 known white dwarfs within about 65 light-years of Earth, then looked further out.
- Most still look white. Only five of the 151 nearby ones had unusual colors, about one in 30.
- A salmon-pink star. WD J1011+2845, about 48 light-years away, gets a deep pinkish color from carbon dredged to its surface. It may be among the reddest stars ever measured.
- Others could appear pink, purple or yellow.
Nobody can see these colors directly from Earth. They were calculated from each star's spectrum, the fingerprint you get when starlight is split by wavelength, then translated into what a human eye would perceive up close.
Why it matters
The colorful white dwarfs are more than a curiosity. Their surfaces act like chemistry labs for destroyed planets. By measuring which elements fell onto the star, astronomers can work out what those rocky worlds were made of.
New spectroscopic surveys are expected to multiply the number of white dwarfs with good spectra roughly tenfold. Hollands has said that could take the count of known green white dwarfs from one or two to perhaps 10 or 20.
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Frequently asked questions
Are there green stars?
Normally no, because stars emit a broad mix of colors that blends to white. The white dwarf WD J1330+6435 is the first known star that would look green.
Why does WD J1330+6435 look green?
Sodium in its helium atmosphere absorbs a wide band of yellow, orange and red light, leaving mostly green.
How far away is the green star?
About 280 light-years from Earth.
Can I see the green star with a telescope?
No. Its color was calculated from spectral data; it is far too faint to see its color by eye.
What will our Sun look like as a white dwarf?
Most likely white. Over 97% of Milky Way stars will end as white dwarfs, and only a small fraction show unusual colors.