Accordingly, the HZ of the red dwarf occupies a range of space roughly ten times closer to its central ball of fire than the HZ in our own solar system. That means the potential for liquid water on the planet's surface.
The star that LHS 1140b orbits is both small and faint.
This also makes studying signals from the planets easier than around more active M-dwarfs.
This planet is located in the liquid water habitable zone surrounding its host, a small, faint red star named LHS 1140.
The study's main author, Jason Dittmann, with the Harvard-Smithsonian Centre for Astrophysics, said that this is the "most interesting" exoplanet that he's seen in the last decade.
A group of scientists have discovered a new "super-Earth" 39 light years away and they say it could be the best candidate yet for a world beyond our solar system that harbours life.
This work led them to discover the planet they call LHS 1140b, transiting the small cool star with a circular orbit.
This latest discovery comes within a year of the revelation that the nearest star beyond our sun, Proxima Centauri, is also orbited by an Earth-size planet, and less than two months after we learned the Trappist-1 system boasts a whopping seven such planets. This planet's large size indicates that a magma ocean may have existed on its surface for eons, feeding steam into the atmosphere and replenishing the planet with water until well within the time the star had cooled to its current, steady glow.
The planet may be 5 billion years old, which is just slightly older than Earth. Its greater mass and density implies that it is probably made of rock with a dense iron core.
In February NASA announced the discovery of TRAPPIST-1, a system of seven Earth-like planets orbiting a Jupiter-sized dwarf star 235 trillion miles away from Earth.
Over the past year, other astronomers have detected potentially habitable exoplanets that are closer, including Proxima Centauri b and the TRAPPIST-1 worlds.
Long-exposure photograph of the MEarth-South telescope array, which helped to find the exoplanet LHS 1140b.
This also allowed them to be sure that the planet is rocky, said HARPS team member Nicola Astudillo-Defru, because HARPS is the most precise instrument that can measure the "wobble" of the planet as the star tugs on it.
The exoplanet therefore lies in the middle of the habitable zone of the star, meaning it has numerous conditions needed to grow alien life.
But if the planet can shield and hide its water source from this heat, it would be saved, Dittman said. If either of those telescopes can't quite suss it out, future telescopes like the James Webb Space Telescope might make it easier. The signal for star LHS 1140 looked like the telltale dip in light that signifies an exoplanet in orbit.
LHS 1140b may seem like it's ideal now, but that wasn't always the case. LHS 1140b is circling a red dwarf star, which emits less heat and light than the Sun.
The scientists aren't wasting any time following up with observations: the next transit (where the planet crosses in front of the star) will occur on October 26 and they've booked several telescopes in Chile to search for signatures of oxygen molecules in the planet's atmosphere. "We don't have atmospheric measurements right now, but the star behaves nicely so that it's not ruling out anything", says Dittman. "We don't know how much water they start with, so it's perfectly feasible that these planets lost lots of water early on, but still managed to hold on to a little bit of water today".