Scientists have discovered Sun-like twin stars, one of which may have ingested a dozen or more of its own rocky planets, located 350 light years from Earth.
The planet-devouring star was named star after Titan Kronos – a mythological character that devoured his children, including Poseidon (better known as the planet Neptune), Hades (Pluto) and three daughters.
The twin star was named after Kronos’ lesser-known brother Krios. Their official designations are HD 240430 and HD 240429.
Researchers from Princeton University in the US confirmed that the widely separated pair about 350 light years from Earth are in fact a binary pair.
They also observed Kronos’ strikingly unusual chemical abundance pattern.
Other co-moving star pairs have had different chemistries, but none as dramatic as Kronos and Krios, said Semyeong Oh, a graduate student at Princeton.
“Most stars that are as metal-rich as Kronos have all the other elements enhanced at a similar level, whereas Kronos has volatile elements suppressed, which makes it really weird in the general context of stellar abundance patterns,” she said.
In other words, 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 – those that are most often found in gas form, like oxygen, carbon, nitrogen and potassium.
Kronos and Krios are far enough apart that some astronomers have questioned whether the two were in fact a binary pair.
Both are about four billion years old, and like our own, slightly older sun, both are yellow G-type stars. They orbit each other infrequently, on the order of every 10,000 years or so.
Binary stars should have matching radial velocities.
Finding matching velocities in the new study supported the theory that Kronos and Krios, though two light years apart, were a binary set.
Then the researchers noticed the extreme chemical differences between them.