“It Feels Like Something Out of Science Fiction”: Astronomers Find First Green Star

Key Points:

• A new study from the University of Warwick reveals that white dwarfs, the dense remnants of stars like our sun, can display a variety of colors beyond plain white, influenced by their atmospheric composition.
• The color variations arise because the dense atmospheres of some white dwarfs contain heavier elements like carbon, calcium, and sodium that absorb specific wavelengths of light, altering their perceived color.
• Using spectral data and models of human color vision, researchers identified unique colors such as chartreuse green and deep salmon pink in certain white dwarfs, with one star (WD J1330+6435) being the first known green star.
• Despite these exceptions, the majority of white dwarfs appear as a cool white color, similar to an LED bulb, with only a small fraction exhibiting extraordinary hues among 151 stars studied within 65 light-years of Earth.
• These findings challenge the traditional view that white dwarfs are uniformly white and suggest that their atmospheric chemistry can create unexpected and diverse visual appearances.