Krios (designated HD 240429) and Kronos (HD 240430) are a wide binary star system in the constellation of Cassiopeia. Both components of the system are yellow G-type main-sequence stars. Originally designated HD 240430 is a Sun-like star in appearance, but it seems to have eaten its own planets, for which it is given the nickname Kronos, after the Greek god and the leader of the first generation of Titans. Its unusual properties were described by a team of astrophysicists at Princeton University in 2017, led by Semyeong Oh.
The names Krios and Kronos both refer to the two Titans in Greek mythology, both of whom were part of the six sons and six daughters of Gaia and Uranus. They were first used for these stars in 2017 and were officially approved by the IAU Working Group on Star Names on 22 March 2026.
Kronos and Krios are about 350 light years away from Earth. Formed around four billion years ago, they originated from the same interstellar cloud. They are moving together through space and are assumed to orbit each other slowly, with an estimated period of about 10,000 years. Kronos has a higher abundance of elements such as lithium, magnesium and iron in its atmosphere than in that of Krios. They are the most chemically different binary stars to have been discovered to date. The unusual and rich chemical composition leads scientists to the conclusion that Kronos has destroyed many of its orbiting planets. According to estimates, it might have absorbed at least 15 Earth masses.