What do you call a runaway exomoon with delusions of planethood? You call it a “ploonet,” of course.
Scientists had previously proposed the endearing term “moonmoons” to describe moons that may orbit other moons in distant solar systems. Now, another team of researchers has coined the melodious nickname “ploonet” for moons of giant planets orbiting hot stars; under certain circumstances, these moons abandon those orbits, becoming satellites of the host star.
The former moon is then “unbound” and has an orbit like a planet’s — ergo, a ploonet.
Ploonets — and all exomoons, for that matter — have yet to be detected. But ploonets may produce light signatures that planet-hunting telescopes could identify, researchers reported in a new study. Their findings were published June 27 in the preprint journal arXiv and have not been peer-reviewed.