A super-Earth has been discovered orbiting in the ‘habitable zone’ of a red dwarf star 137 light years away. The system could also host a second Earth-sized planet.
Called TOI-715 b, the super-Earth is about one and a half times wider than Earth and orbits at the distance from the star that could give the planet the right temperature for liquid water to form on its surface. The smallest planet could be only slightly larger than Earth and could also live just inside the habitable zone.
This discovery was made possible thanks to data from NASA’s TESS exoplanet hunter, analyzed by scientists led by Georgina Dransfield of the University of Birmingham who published results in the journal Monthly Notices of the Royal Astronomical Society.
According to NASA, TOI-715 b could be making its appearance at just the right time. Its parent star is a red dwarf, smaller and cooler than our Sun; Several of these stars are known to host small rocky worlds.
At the moment, they are the best bet for finding habitable planets. These planets have much closer orbits than those surrounding stars like our Sun, but because red dwarfs are smaller and cooler, the planets can be clustered closer together and still be safely within the star’s habitable zone.
Narrower orbits also mean that those that cross the faces of their stars (that is, when viewed with our space telescopes) intersect much more frequently. In the case of planet b, that’s once every 19 days, a “year” on this strange world. Therefore, these star-crossing (“transiting”) planets can be detected more easily and observed more frequently