The first known genuinely green star is WD J1330+6435, a cool white dwarf (the dense remnant of a Sun-like star) studied by a University of Warwick team led by Dr Mark Hollands. In research published in RAS Techniques and Instruments and announced on October 15, 2026, the team found that the star would look chartreuse green to the human eye. The researchers say no other star, living or dead, has ever been credibly reported as green.
The color comes from its atmosphere rather than its temperature of roughly 4,000 °C. The white dwarf has pulled in rocky debris from its old planetary system, which added sodium, calcium and lithium. In the extremely dense helium atmosphere, the sodium absorbs orange, yellow and red light, leaving a green glow. Because no white dwarf is close enough to see its color directly, the team worked the color out from the star’s spectrum using a model of human color vision.
Image: Sirius A and its white dwarf companion Sirius B (the small dot at lower left), NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester), public domain, via Wikimedia Commons. This is not WD J1330+6435.
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