Astronomers discover a white dwarf that appears green after consuming planetary debris

Astronomers have identified WD J1330+6435, a white dwarf located about 280 light-years from Earth, whose spectrum is predicted to appear chartreuse green. Its unusual colour results from sodium in its dense atmosphere absorbing a broader range of yellow, orange and red wavelengths after collisions with helium atoms. The star has accumulated rocky planetary debris containing sodium, calcium and lithium. We explore how this unusual chemistry changes the star’s apparent colour, what other strangely coloured white dwarfs reveal, and how their atmospheres preserve clues about planetary systems around dying stars. Video Credit: University of Warwick / Mark Hollands and Boris Gänsicke (research and scientific visualisations);, GettyImages, Phys.org, AI generated visuals (Google Gemini & Chatgpt)