The planet is part of a small set of objects with size and orbit similar to those of Earth.
“To have an idea of the rarity of the detection, the time it took to observe the magnification due to the host star was approximately five days, while the planet was detected only during a small five-hour distortion,” said Antonio Herrera Martin, leader of the research, in a statement. “After confirming this was indeed caused by another ‘body’ different from the star, and not an instrumental error, we proceeded to obtain the characteristics of the star-planet system.”
Using the Solar System as a reference, astronomers calculated that the super-Earth’s host star has about 10% of the mass of our Sun, while the planet has a mass between Earth and Neptune and an orbit of 617 days. The distance between the planet and its star is equivalent to the space that exists between the Sun and the area between Venus and Earth.
According to Herrera Martin, the planet was discovered using a technique called gravitational microlensing, which is extremely specific – only one in a million stars in our galaxy can be detected by the method. “The combined gravity of the planet and its host star caused the light from a more distant background star to be magnified in a particular way. We used telescopes distributed around the world to measure the light-bending effect,” explained the scientist.