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Dead white dwarf would glow a startling chartreuse green
Its dense atmosphere absorbs orange and violet light, letting green break through, the researchers say.
26 Oct 2026 0 reads Compiled with AI
Astronomers have found a dead star that would glow a striking shade of chartreuse. The object, WD J1330+6435, has a surface temperature of 4,240 K and would appear chartreuse green to the naked eye. The researchers say its color is the "most surprising color" they found.
How the green glow forms
White dwarfs are the exposed cores of former stars, packed with up to 1.4 solar masses into a body about the size of Earth. Their gravity squeezes the outer layers, so even the coolest white dwarfs have atmospheres as dense as liquid water. At such densities, atoms are crowded together, which changes how they absorb light.
In WD J1330+6435, the dense atmosphere contains sodium and calcium. Sodium absorbs a broad band of orange-yellow light, while calcium suppresses violet, and green gets through. Astronomers have also detected lithium, another element linked to rocky material, which suggests the star may have consumed debris from its former planetary system.
Of a sample of 152 nearby white dwarfs, only five, roughly one in 30, had colors significantly different from those expected from temperature alone. Not every unusual hue points to planetary material, but the colors could help astronomers study the remains of dead planetary systems. The research has been published in RAS Techniques and Instruments.