Scientists reveal first zombie star with ghostly green glow and fascinating reason behind hue: Something out of science fiction

Astronomers have discovered the first white dwarf “zombie” star with a “ghostly green glow” that they say it got from eating the rocky debris of dead planets.“It feels like something out of science fiction,” said astrophysicist Mark Hollands, whose team from the University of Warwick announced its findings last week.The zombie WD J1330+6435 is in the Milky Way, although about 280 light-years from our solar system, and can be faintly seen in the constellation Draco, the scientists said.The discovery marked the first time researchers have seen a “green” star — and discovered that the color of such super-dense “zombie” stars can be changed by elements it absorbs such as carbon, calcium, and sodium.“Most stars, including most white dwarfs, behave like ‘perfect radiators,’ so their color is set almost entirely by temperature,” Hollands told Space.com, explaining that cool stars look orange and hot stars appear pale blue.“But nobody had really looked into what else might be possible for white dwarfs.

“It turns out these incredibly dense stars can produce colors nobody expected, and some of them genuinely surprised me.“The traces of sodium in the atmosphere of this white dwarf absorb the orange part of the spectrum, leaving behind a ghostly green glow,” Hollands said.“Imagine standing on a planet and looking up at a green star.”White dwarfs in general are the leftover stellar core of a star that has stopped producing nuclear fuel and shed its outer layer during its red-giant phase.Without fusion to sustain itself, it devours planets, asteroids and other heavenly bodies that get pulled into its supercharged gravity, leading it to be called a “zombie” star in the phase because it “lives” after “death.”One of those celestial snacks — rocky material from a nearby planet containing calcium, lithium, and sodium — turned WD J1330+6435 green, scientists said.Dwarf stars that have consumed high levels of carbon would be pi...