An illustration of newly discovered exoplanets. Photo: Robin Dienel, courtesy of the Carnegie Institution for Science.
Among several newly discovered exoplanets, there are two that potentially have the conditions for life. They revolve around red dwarfs near our solar system.
A team led by scientists Fabo Feng and Paul Butler at the Carnegie Institution of Science has discovered the two planets where there can be some kind of life. The study is published in The Astrophysical Journal.
The planets orbit around the red dwarfs GJ229A true GJ180, located 19 and 39 light years from Earth, respectively. It can be compared to our nearest star Proxima Centauri at 4.2 light years away.
Planets in the viable zone around red dwarfs are often gravitationally locked, which means that the planet’s day side is constantly facing the star. So they have a page where it is permanently day and a page in constant darkness. This is not an optimal condition for life.
But the two newly discovered planets are at a distance from their star which means they do not have a locked side.
– GJ180 d is the temperate super-Earth that is closest to us and is not gravitationally locked to its star, which probably increases the likelihood that it will be able to live, says Fabo Feng on Carnegie’s website.
By super earths is meant that their mass is larger than our planet but smaller than our solar system’s smaller gas giants, Uranus and Neptune. In this case, the mass of the GJ180 d is at least 7.5 times greater than that of the earth, and the mass of the GJ229A is 7.9 times greater than that of the earth.
Since the two planets are located in solar systems relatively close to our own sun, there are good conditions for observations with the new generation of space- and ground-based telescopes available.
The planets were found by the Carnegie Planet Finder Spectrograph using the radial velocity method, where you study how gravity causes the star to move around the center of gravity on a very small scale – that the star “swings”.
Red dwarfs are the most common stars in our galaxy, and with their low mass they are the category where the probability is greatest to find planets close to the size of the Earth with existing technology.
The star type also offers most planets with the right conditions for liquid water. The orbits of the planets may be smaller than the Earth’s, but still be in the viable zone. For example, the newly discovered worlds take 106 as well as 122 days for a lap around the star.