Every exoplanet is special in its own way, but a newly discovered exoplanet 186 light-years away is an especially delicious treat. It's a smallish world around the same size as Earth, whipping around its star on an orbit that takes just 3.14 days.
That's extremely close to the mathematical constant π (
Pi), the number that describes the ratio of a circle's circumference to its diameter. So, even though the exoplanet's official name is K2-315b, its discoverers have nicknamed it "π Earth."
The discovery of the star has been several years in the baking. The first hints of its existence emerged back in 2017, when the Kepler Space Telescope (
RIP) was conducting its second, extended mission.
In the light of a small, dim red dwarf star just 20 percent the size of the Sun, Kepler detected 20 tiny dips at regular intervals. This is the main way we search for exoplanets - such dips often mean that a planet is crossing between us and the star in question, something known as a transit. Those transits register as very slight fluctuations in starlight.
But just one collection of dips isn't enough to confirm an exoplanet detection, so, armed with the Kepler data, astronomer Prajwal Niraula and his colleagues set out earlier this year to study the star with SPECULOOS.
This is a network of telescopes working together to specifically search for Earth-sized exoplanets around dim dwarf stars.
www.sciencealert.com