New exoplanets are discovered every week, but this one is quite unique. This exoplanet, in addition to being Earth-like, orbits a star that is similar to the Sun.
Analyzing data from the Kepler mission, a team of researchers identified a planet similar to Earth, KOI-456.04, located in the habitable zone of its star, Kepler-160. The results of the discovery were recently published in the scientific journal Astronomy and Astrophysics.
“KOI-456.01 is relatively large compared to many other planets that are considered potentially habitable. But it’s the combination of this less-than-double the size of the Earth planet and its solar type host star that make it so special and familiar,” said lead author René Heller, of the Max Planck Institute for Solar System Research, in Germany.
Located more than 3,000 light-years from Earth, Kepler-160 is about 1.1 times the size of the Sun and has a surface temperature of 5200˚C, only 300 degrees less than our star.
Astronomers were already aware of two exoplanets in the system – Kepler-160 b, a rocky super-Earth, and Kepler-160 c, a Neptune-like gas giant – but their orbits are very close to the star and are likely to be too warm to be habitable.
However, the team created a new, more accurate search algorithm, capable of identifying the presence of smaller planets. Using this algorithm, they found KOI-456.04. With an orbital period very similar to that of the Earth, of 378 days, this planet is at a distance from Kepler-160 that allows the existence of liquid water.
In addition, KOI-456.04 may receive about 93% of the amount of sunlight we do on Earth. The researchers suggest that if it had an inert atmosphere with a greenhouse effect similar to that of our planet, its surface temperature would be about 5°C, approximately 10°C less than the average temperature we are used to.
Further analysis revealed a fourth planet, Kepler-160 d, responsible for the variations previously observed by scientists in the Kepler-160 c orbital period. This planet has between one and 100 Earth masses and an orbital period of 7 to 50 days.
However, it was KOI-456.04 that caught the attention of astronomers, although they are still not 100% sure that it is a planet. The team believes that they will have to wait for future space missions, like the European Space Agency (ESA) PLATO spacecraft, to confirm the discovery.