Astronomers using the TRAPPIST telescope at the ESO’s La Silla Observatory in Chile found their view of the star was obscured at regular intervals, meaning that objects were passing between the star and the Earth.

Dubbed TRAPPIST-1, the ultra-cool red dwarf is located in the constellation of Aquarius. While stars of that type are very common in the Milky Way, this is the first time one of them has been found to have planets.

The team used the giant HAWK-I instrument, also at La Silla, to determine the size of the three planets and the duration of their respective orbits.

The planets are between 20 and 100 times closer to TRAPPIST-1 than the Earth is to the Sun.

Several giant telescopes currently under construction are expected to enable astronomers to make a detailed study of the planets and their atmosphere in search of indicators pointing to the presence of water and, ultimately, biological activity.