Astronomers discover white dwarfs can shine in green, pink and purple hues

Using advanced spectroscopic techniques, the Warwick team analysed the light emitted by several nearby white dwarf stars, uncovering variations in temperature and atmospheric composition that produce distinct colour signatures. One star, in particular, exhibited a peak emission in the green portion of the visible spectrum, a phenomenon previously thought impossible for such dense stellar objects. The discovery challenges conventional models that predict white dwarfs to appear uniformly white or bluish due to their high surface temperatures.

The researchers attribute the colour diversity to subtle differences in elemental abundances, magnetic fields, and surface gravity, which alter the absorption lines and shift the perceived hue. By cataloguing these spectral fingerprints, astronomers can refine age estimates for white dwarfs and, by extension, the stellar populations of the Milky Way. The study also opens avenues for investigating exotic physics under extreme conditions, as the behaviour of matter in white dwarf atmospheres offers clues to quantum mechanical processes.

In the broader astronomical community, the revelation is expected to stimulate a wave of targeted observations, employing both ground‑based telescopes and space‑borne instruments to map the colour distribution of white dwarfs across the galaxy. This could ultimately enhance our understanding of stellar evolution pathways and the chemical enrichment history of the cosmos, reshaping textbooks that have long portrayed these remnants as uniformly colourless.