Astronomers Reveal Rare and Surprising Colors of White Dwarfs

A research team led by Dr. Mark Hollands translated white dwarf spectra into colors as human vision would see them. Most nearby white dwarfs have perceived colors close to a thermal emitter at about 6,800 K, but a small minority depart sharply from that norm. Examples include a deep salmon-pink white dwarf with carbon in its atmosphere and a green white dwarf whose sodium absorption removes orange light.

Dr. Mark Hollands led a University of Warwick team that converted white dwarf spectra into human-perceived colors. Among 152 white dwarfs within about 65 light-years, the median hue matched a thermal emitter near 6,800 K, close to computer-screen white. Only five stars, roughly 3%, departed far from that norm.

WD J1011+2845, 48 light-years away, appears a rich pink with salmon tones; convection likely lifted core carbon to its surface, and carbon molecules shift much light beyond 600 nm. WD J1330+6435 looks green because sodium in its dense atmosphere absorbs orange wavelengths. Another cool star, WD J2356-2054, appears bright blue near 4,000 K. The findings appeared in RAS Techniques and Instruments.