An international team of scientists announced Tuesday that the habitable zone of a nearby star is home to three planets that could support life.
These three "Super-Earths," as the planets are known, are part of a "dynamically packed planetary system" of at least six planets orbiting a star that exists 22 light years from Earth, according to the report. Super-Earths are planets that are bigger than Earth, but smaller than planets like Uranus or Neptune, according to the European Southern Observatory.
The "habitable zone" of the star, Gliese 667C, is the temperature region where liquid water could exist, according to Space.com. Gliese 667C is part of a three-star system, so the planets could see three suns in their daytime skies.
Mikko Tuomi, a researcher at the University of Hertfordshire and a co-author of the report, said in a released statement that researchers knew from previous studies that the star had at least three planets.
"We wanted to see whether there were any more," Tuomi said. "Finding three low-mass planets in the star's habitable zone is very exciting!"
Gliese 667C is the faintest star in the three-star system, according to ESO scientists.
Although compact systems around sun-like stars have been found to be abundant in the Milky Way, planets orbiting those stars are very hot and unlikely to be habitable, according to ESO scientists. But this was not the case for Gliese 667C, which is cooler and dimmer than the sun, making it possible for certain planets to remain habitable.
This is the first time that three such planets have been spotted orbiting in the habitable zone in the same system. In April, NASA announced a similar discovery in the habitable zone of another star, Kepler 62, but that discovery only tallied two planets, according to The Atlantic.
"The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star," said Rory Barnes, the study's co-author. "Instead of looking at 10 stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them."
The researchers used various telescopes, including one at the Silla Observatory in Chile that incorporates the high-precision Harps instrument, according to BBC News. This telescope uses an indirect method of detection that infers the existence of orbiting planets based on the way their gravity makes a parent star appear to twitch across the sky.
"These new results highlight how valuable it can be to reanalyze data in this way and combine results from different teams on different telescopes," said co-author Guillem Anglada-Escudé, in the statement.