October 23, 2026 — Stars may be red, blue or white, according to the familiar astronomy lesson. Green? Usually not. Yet a newly published study makes a case for a distinctly green-looking stellar remnant—and that is not even the strangest color its authors found.
On October 22, NASA’s Astronomy Picture of the Day highlighted WD J1330+6435, a white dwarf whose predicted appearance challenges the standard palette of stars.
Why a “white dwarf” might look green
White dwarfs are the dense remnants of stars that have exhausted their nuclear fuel. Their unusual atmospheric pressure changes how matter absorbs and transmits light. Researchers from the University of Warwick analyzed stellar spectra—measurements of light split by wavelength—and modeled how those spectra would look to human vision at sufficiently close range.
One example, WD J1330+6435, appears green in the calculations because sodium-rich rocky debris incorporated into its atmosphere absorbs a broad swath of yellow, orange and red light. What’s left produces a greenish visual impression.
The team also identified model colors including pink, purple, cyan and yellow in certain white dwarfs. Carbon and other atmospheric ingredients can dramatically reshape the light that emerges.
Not a photograph of a neon-green sun
There is an essential caveat: astronomers have not photographed a green stellar disk from nearby, and viewers on Earth cannot simply point a backyard telescope upward and see WD J1330+6435 glowing like a traffic signal.
The conclusion comes from measured spectra and models of human color perception, not a direct close-up picture. The NASA illustration credited to Mark A. Garlick and the University of Warwick is artwork depicting the calculated appearance.
The authors’ sample of 151 nearby white dwarfs found five unusually colored examples—two yellow and three pink—while the average white dwarf remained essentially white. Unusual colors are possible, but they are not the norm.
The bigger mystery: what happens to dead solar systems?
The green tint carries a deeper implication. Rocky material, potentially remnants of a disrupted planetary system, can fall into a white dwarf’s atmosphere and change its light. In other words, starlight can preserve chemical hints about worlds long gone.
The peer-reviewed research, Any colour you like: the diverse chromaticities of white dwarfs, was published October 15 in RAS Techniques and Instruments.
The Apep Bar question: If even a dead star can hide an unexpected color, what else is the universe disguising in plain sight?
Sources and study
- Peer-reviewed study, October 15, 2026
- University of Warwick research release, October 2026
- NASA Astronomy Picture of the Day, October 22, 2026
Featured image: general illustrative space photograph; it does not depict WD J1330+6435. Photo: Shot by Cerqueira / Unsplash. NASA’s original commissioned artwork is linked above rather than reproduced.
