Astronomers at the University of Warwick say they have identified the first star known to appear genuinely green. The object, a cool white dwarf named WD J1330+6435, would glow a yellowish green to human eyes because sodium pulled from the rocky remains of its planetary system has polluted its atmosphere, according to research published this week in the journal RAS Techniques and Instruments.

There is an important qualifier in that claim. Nobody has seen this star glowing green through a telescope eyepiece. The team calculated its true color from measured starlight and models of human vision, because no white dwarf sits close enough for people to judge its color directly.

The finding matters beyond a striking image. White dwarfs are what stars like our Sun become after they die, and their polluted atmospheres are one of the few ways astronomers can study what the rocky worlds of other star systems were made of.

A Sodium Glow From a Stellar Corpse

According to a University of Warwick summary on Phys.org, WD J1330+6435 has accreted sodium-rich rocky material from its planetary system. Its atmosphere is so dense that the sodium absorbs light across a broad range of yellow, orange, and red wavelengths, leaving a greenish glow.

The star is about 4,000 degrees Celsius (roughly 7,200 degrees Fahrenheit), far cooler than our sun's surface, and sits around 326 light-years from Earth, according to Space.com. Its atmosphere also carries calcium and lithium from the same accreted material.

Lead author Mark Hollands said the sodium absorbs the orange part of the spectrum, "leaving behind a ghostly green glow." As far as the researchers know, no other star, living or dead, has been credibly reported as green.

Planet Debris, Not a Swallowed Planet

Some headlines have described this star as a cosmic zombie that ate its planets. The evidence supports a more measured version. The material in its atmosphere came from rocky bodies in its planetary system, but the research does not show that whole planets were swallowed in one event.

White dwarfs pull in fragments of asteroids and other rocky debris that stray too close. Their gravity is so strong that heavy elements normally sink out of view quickly, so seeing them in the atmosphere means the star has been taking in material recently by astronomical standards.

This particular white dwarf was already known for that pollution. Earlier work by Hollands and colleagues, summarized in a 2024 study of lithium-polluted white dwarfs, linked lithium-rich debris around several such stars to material resembling continental crust from Earth-like planets. That makes WD J1330+6435 a natural laboratory for studying rocky planets that no longer exist.

Most Dead Stars Still Look White

The study was not limited to one green star. The team modeled the colors of white dwarfs and found that dense atmospheres can shift them toward pink, purple, cyan, and yellow, breaking the usual rule that a star's color tracks its temperature.

They also flagged what may be the reddest star ever recorded. WD J1011+2845, about 48 light-years away, has carbon dredged up from its interior that pushes nearly all of its light toward longer wavelengths, giving it a deep salmon-pink tone.

Unusual colors appear to be rare, though. Only five of the 151 white dwarfs within about 65 light-years of Earth showed them, which the team extrapolates to roughly one in 30 across the population. Co-author Boris Gänsicke told Space.com that, taken as a whole, "the average white dwarf really is white."

The evidence here is computational. The colors are predictions from spectra and vision models rather than direct observations, and they assume the atmospheric models are correct. The green result is also based on a single object, so the researchers present it as the first known example rather than the start of a common class.

Our Sun's Distant Future and the Night Sky

For most readers, the closest connection is our own star. The Sun is expected to become a white dwarf billions of years from now. Whether it ever looks green would depend on what rocky debris it pulls in, a question far beyond any human timescale.

There is nothing to look for in the backyard sky. WD J1330+6435 is far too faint for the naked eye or a typical home telescope, and even large observatories record its light as spectra rather than a visible color. Claims online of seeing a green star are not connected to this research.

For anyone interested in the topic, local astronomy clubs and planetariums often host public viewing nights where volunteers explain how astronomers read the chemistry of distant stars from their light. Those events are a reliable alternative to viral posts that misdescribe space discoveries.

The research also adds to a broader field. White dwarf pollution offers one of the few direct ways to measure the chemistry of rocky exoplanet material, complementing missions that study planets around living stars. Each polluted white dwarf effectively preserves a sample of a destroyed world's composition.

The next step is broader testing. The Warwick team's color models can be applied to larger white dwarf samples from surveys such as Gaia, and follow-up spectroscopy could identify more unusually colored stellar remnants. Nature World News will report on any confirmed additions.

The takeaway is simple. A white dwarf about 326 light-years away appears to be the first known green star, but its color comes from careful modeling of debris left by its planetary system, not a direct sighting or a planet-swallowing spectacle. Most dead stars, the same study shows, remain reassuringly white, just as their name suggests.

What Readers Want to Know

What is the first green star?

It is WD J1330+6435, a cool white dwarf about 326 light-years away that University of Warwick researchers say would appear yellowish green to human eyes.

Why is the star green?

Sodium from accreted rocky debris absorbs yellow, orange, and red light in its dense atmosphere, leaving a greenish color.

Did anyone actually see the star glowing green?

No. The color was calculated from measured spectra and models of human color vision, because white dwarfs are too far away to view their true color directly.

Did the star eat its planets?

The research shows it accreted rocky material from its planetary system. It does not show that whole planets were swallowed at once.

Can I see the green star from my backyard?

No. It is far too faint for the naked eye or typical home telescopes.

Will our sun turn green?

The sun will become a white dwarf billions of years from now. Its color would depend on what material it accretes, which cannot be predicted.