While learning about the potential super-Earth exoplanet - super-Earth meaning it has a mass similar to Earth - scientists discovered that there could be another exoplanet orbiting its same parent star.
Experts discovered the distant exoplanet - known as K2-18b - is a flawless candidate for hosting other life and is made out of rock like Earth. Study co-author Rene Doyon says that K2-18b will be a prime candidate for the new telescope's atmospheric studies of distant planets once it comes online.
The two new super-Earths orbit a red-dwarf star around 111 light years away. The Planet K2-18b, as they have already called it, wanders around a star-dwarf and even within the zone where life can develop.
K2-18b was first spotted by the astronomers in 2015. The K2-18b orbits a star called K2-18 at around 111 light-years away from our planet Earth. Water, as we know it, is a key component for the possibility of life.
But scientists weren't sure if the planet was a scaled-up version of Earth (a rocky or terrestrial planet) or a scaled-down version of Neptune (a gas and ice planet).
"Being able to measure the mass and density of K2-18b was tremendous, but to discover a new exoplanet was lucky and equally exciting", stated lead author Ryan Cloutier, an astronomy and astrophysics Ph.D student at the University of Toronto and the University of Montreal's Institute for Research on Exoplanets.
The study conducted by the University of Toronto and the University of Montreal, Canada was in collaboration with a dataset coming from the High Accuracy Radial Velocity Planet Searcher (HARPS) which used the European Southern Observatory's 3.6-metre telescope at La Silla Observatory in Chile.
"So if we can detect that wobble, we can infer the presence of a planet, like this super-Earth, and we can actually measure its mass, which is great, because it tells you something about how big the planet is", Cloutier explained.
"It wasn't a Eureka! moment because we still had to go through a checklist of things to do in order to verify the data", Cloutier noted. "But with the James Webb Space Telescope (JWST) we can probe the atmosphere and see whether it has an extensive atmosphere or it's a planet covered in water".
It was while looking through the data of K2-18b that Cloutier noticed something unusual.
On top of that, the radial velocity measurements discovered by HARPS allowed researchers to calculate planets' mass, enabling them to measure their bulk density, and thus whether they are gaseous, rocky, whether they contain water, etc.
In addition to a signal occurring every 39 days from the rotation of K2-18, and one taking place every 33 days from the orbit of K2-18b, they noticed a different signal occurring every 9 days.
Other researchers on the team are affiliated with the Geneva Observatory in Switzerland, France's University of Grenoble, and the University of Porto in Portugal.