An international team of researchers has announced the discovery of a previously unknown super-Earth whose orbit passes through the so-called habitable zone. The discovery is interesting because it was made using a rare method.
The two most popular methods for detecting exoplanets (transit and radial velocity measurements) have a number of significant limitations. The first one needs the exoplanet’s orbit to line up perfectly with the line of sight, which is super rare, especially for planets with long orbital periods. The second method has a number of difficulties in detecting weak signals from low-mass bodies, especially if they are in distant orbits.
All this forces researchers to look for alternative methods. One of them is the transit variation method. It is suitable for systems in which there is a known transiting exoplanet. If its transits do not occur strictly according to “schedule,” this may indicate the presence of other bodies whose gravity affects the orbit of the observed exoplanet.
Until recently, only large gas giants were considered using the transit variation method. However, researchers have now made a breakthrough and used it for the first time to detect a super-Earth.
The newly discovered body orbits around the yellow dwarf Kepler-725, located 2,500 light-years from Earth. Previously, astronomers managed to find a transiting gas giant in this system. By studying the deviations in the timing of its transits, they were able to prove the existence of at least one more exoplanet. It was designated Kepler-725c.
Kepler-725c is a super-Earth. Its mass is 10 times greater than that of our planet, and its orbital period is 207.5 days. Kepler-725c moves in a fairly elongated orbit, part of which passes through the habitable zone. On average, it receives 1.4 times more energy from its star than Earth does.
According to researchers, Kepler-725c is most likely a mini-Neptune rather than a rocky planet. Nevertheless, this discovery is very important because it fills a critical gap among existing methods for searching for exoplanets, providing a promising alternative for finding potentially habitable worlds.
Earlier, we reported on whether space travel could exist on super-Earths.
According to Eurekalert
