Stellar Siblings found; both have planets

Scientists don’t go looking for coincidences, and in general, when we find them, we don’t trust them to be more than accident and chance. But sometimes…. Just sometimes, the things we find are actually related.

Enter astronomers Jason Curtis and Marcel Agueror. Working in a larger, multi-institutional team, these scientists were doing followup work on the planet having systems, Kepler 52 and Kepler 968. Both these systems have 3 planets orbiting a K-Dwarf star — a star cooler and smaller than our Sun that is capable of living for billions of billions of years without showing its age.

Artist’s Illustration: Twin K-Dwarfs Kepler-52 and Kepler 968 were found to both have 3 planets, and to both be members of the newly discovered star cluster Theia 520. Credit: Pamela L. Gay

This last characteristic is actually a bit problematic. When we look at systems with K-Dwarf stars, we can’t easily measure their age — by which I mean we can’t measure their age. Instead, we guess, based on where they are, and what they seem to be related to.

And sometimes we guess wrong.

Going into this study, it was thought K-52 and K-968 were several billion years old, and utterly unrelated — simply strangers passing in the night through the original Kepler observing field. This star field, however, is located in the region of the sky being studied by the Gaia space telescope, a telescope that can very precisely measure stellar distances, brightnesses, and motion.