White dwarf stars can exhibit unexpected colors

New research from the University of Warwick suggests that white dwarf stars can display a much wider range of colors than previously assumed, including green, pink, and violet. While stellar color is typically determined by temperature—with cooler stars appearing orange or red and hotter stars appearing white or blue—white dwarfs are influenced by their unique atmospheric compositions.

Scientists found that certain white dwarfs rich in carbon may appear pink or violet. Other stars, which have absorbed rocky debris from former planets or asteroids, can take on yellow, blue, or even green hues. A notable example is WD J1330+6435, which has enriched its atmosphere with elements like calcium and sodium from its former planetary system, resulting in a pale green appearance similar to chartreuse. Another star, WD J0902+2010, is expected to appear pink due to carbon rising from the star's depths absorbing specific light frequencies.