Starship Asterisk*

Two binary stars, now far apart, skated by one another 2-3 million years ago, leaving a smoking gun: a disordered planetary system (left).

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Some of the peculiar aspects of our solar system — an enveloping cloud of comets, dwarf planets in weird orbits and, if it truly exists, a possible Planet Nine far from the sun — have been linked to the close approach of another star in our system’s infancy that flung things helter-skelter.

But are stellar flybys really capable of knocking planets, comets and asteroids askew, reshaping entire planetary systems?

UC Berkeley and Stanford University astronomers think they have now found a smoking gun.

A planet orbiting a young binary star may have been perturbed by another pair of stars that skated too close to the system between 2 and 3 million years ago, soon after the planet formed from a swirling disk of dust and gas.

If confirmed, this bolsters arguments that close stellar misses help sculpt planetary systems and may determine whether or not they harbor planets with stable orbits. ...

• arXiv.org > astro-ph > arXiv:1902.10220 > 26 Feb 2019