No, it’s not Marvel’s Galactus “The Devourer of Worlds,” but these two stars have devoured up to 15 planets so far! They’re named Kronos and Krios after the Greek Titan that ate children and they orbit each other every 10,000 years.
Surprisingly, NASA didn’t catch these giant stars destroying planets not too far away. A team of researchers from Princeton University spotted them.
“Even if our sun ate the entire inner solar system, it wouldn’t come close to the anomaly we see in this star,” said David Hogg from the Center for Computational Astrophysics (CCA).
These two stars are moving as a pair in a binary system but their compositions are distinctly different from each other, leading to the discovery of their enormous appetites.
Stars HD 240430 and HD 240429, better known as Kronos and Krios, as they appear in the Space Telescope Science Institute’s Digitized Sky Survey. Though these binary stars formed together, their chemical abundances are very different, leading researchers to conclude that Kronos had absorbed 15 Earth masses worth of rocky planets.Image courtesy of the researchers
“I’m very easily excitable, so as soon as they had the same radial velocities and different chemistry, my mind already started racing,” said Adrian Price-Whelan, a Lyman Spitzer, Jr. Postdoctoral Fellow in Astrophysical Sciences and a co-author on the paper.
The researchers found traces of planets inside the stars. Kronos had an unusually high level of rock-forming minerals, including magnesium, aluminum, silicon, iron, chromium, and yttrium, without an equally high level of volatile compounds — usually found in gas form, like oxygen, carbon, nitrogen, and potassium.
“All of the elements that would make up a rocky planet are exactly the elements that are enhanced on Kronos, and the volatile elements are not enhanced, so that provides a strong argument for a planet engulfment scenario, instead of something else,” said Semyeong Oh from Princeton University, the lead author of the study.
Thank goodness these two stars are not headed towards our earth.