Located 226 light-years away in the constellation Taurus, the newly-discovered planet orbits the fainter member of the K2-288 binary system.

This system contains a pair of dim, cool M-type stars separated by about 5.1 billion miles (8.2 billion km), roughly six times the distance between Saturn and the Sun.

The brighter star, K2-288A, is about half as massive and large as the Sun, while its companion, K2-288B, is about one-third the Sun’s mass and size.

“The candidate planet was first identified by citizen scientists using Exoplanet Explorers hosted on the Zooniverse platform,” said University of Chicago graduate student Adina Feinstein and colleagues.

“Follow-up observations and detailed analyses validate the planet and indicate that it likely orbits the secondary star on a 31.4-day period.”

“This orbit places K2-288Bb in or near the habitable zone of its low-mass host star.”

K2-288Bb has a radius of about 1.9 times that of Earth, which places it in the so-called Fulton gap — a likely transition zone between rocky super-Earths and gaseous sub-Neptunes.

“Among planets that orbit close to their stars, there’s a curious dearth of worlds between about 1.5 and two times Earth’s size,” the astronomers explained.

“This is likely the result of intense starlight breaking up atmospheric molecules and eroding away the atmospheres of some planets over time, leaving behind two populations.”

“Since K2-288Bb’s radius places it in this gap, it may provide a case study of planetary evolution within this size range.”

The discovery is reported in a paper in the Astronomical Journal.

Source: Sci News