Astronomers Identify Rarely Colored White Dwarfs, Including a Potentially Green Star
Researchers have catalogued a handful of white dwarfs that would appear green, pink, purple or yellow to human eyes, a rarity among the 151 nearby stars studied.
In a study published in RAS Techniques and Instruments, astronomers from the University of Warwick analyzed the light from 151 nearby white dwarfs and identified five that would display atypical colors to the human eye. The most striking example, WD J1330+6435, has a temperature around 4,000 °C and contains calcium, lithium and sodium; dense helium collisions shift sodium’s absorption, giving the star a green hue. A second object, WD J1011+2845, located about 48 light-years from Earth, shows a deep salmon-pink shade caused by carbon on its surface.
Other carbon-rich dwarfs may appear pink or purple, while those with debris from shattered bodies look yellow, and some hydrogen-helium atmospheres appear cyan or pale blue. The researchers used established spectral-to-color models to translate the measured wavelengths into perceived colors, confirming the reliability of their predictions. Although most white dwarfs remain white, the discovery highlights how extreme density can produce unexpected visual effects and may help trace planetary debris in former solar systems.
Why it matters
The study shows how extreme stellar conditions can produce visible colors, offering a new way to understand white dwarf composition and planetary remnants.
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