White dwarf stars show unusual colors

Astronomers from the University of Warwick discovered that some white dwarf stars appear green, pink, or violet, according to a study published in the Royal Astronomical Society Techniques and Instruments on October 15, 2026. The study analyzed the light spectra of these dead stars and translated them into colors humans can perceive.

Green star identified

One example is a green star named J1330, whose atmosphere contains a high amount of sodium. This element filters the light in such a way that the star appears green to the human eye, despite the usual rules of stellar color.

Traditional view on star colors

For years, astronomers believed green stars were impossible. This was because the color of a typical star depends mainly on its temperature, which determines the peak wavelength of its light. Hot stars emit light that peaks in the blue range, while cooler stars peak in the red range, following a pattern known as the black body curve.

Human perception limits color perception

Even though the light from a star may have a peak in the green part of the spectrum, the human eye typically perceives only white, blue, orange, or red. This is because the light from ordinary stars is scattered and absorbed by their atmospheres, which prevents the green color from being visible to observers.

White dwarfs break the rules

White dwarfs, the remnants of stars like the Sun, change this dynamic. When a star like the Sun dies, it sheds its outer layers, revealing a hot core that cools over time. This process allows for different atmospheric compositions that can alter how the star’s light is perceived, making colors like green possible.