Researchers from the University of Liege in Belgium have detected three new Earth-sized planets that may host alien life.

According to the publication Business Standard, the team of astronomers led by Michael Gillon of the Institute d'Astrophysique et Geophysique used the Belgian TRAPPIST telescope to observe the star 2MASS J23062928-0502285. The star is also known by the name of TRAPPIST-1.

The astronomers found that, at regular intervals, the TRAPPIST-1 star that is dim and cool faded slightly. This observation is an indicator that several objects were passing between Earth and the star.

TRAPPIST-1 is an ultra cool dwarf star, barely larger than Jupiter and much redder than the Sun. After a more detailed analysis, the scientists deducted that there were three planets present with similar size to the Earth.

Despite being so close to the Earth, researchers observed that the TRAPPIST-1 star is too red and too dim to be seen with the naked eye. The star cannot even be observed with a large amateur telescope. According to astronomers, TRAPPIST-1 is located in the constellation of Aquarius.

The planets orbiting TRAPPIST-1 have very similar sizes to that of our planet. The orbital periods of two of the planets are about 2.4 days and 1.5 days, respectively. The orbital period of the third planet could be less well determined in the 4.5 to 73 days range.

The dwarf star with the three Earth-sized planets orbiting planets is less than 40 light years away. This would make the first time when planets have been found around this type of star.

The discovery opens up new possibilities in the search for extraterrestrial life. It is estimated that around 15 percent of the stars near our Sun are also similar ultra cool dwarf stars.

Fox News reports that currently, scientists are making atmospheric observations of the three temperate exoplanets using NASA's Spitzer Space Telescope. Next week will also join in the study the Hubble Space Telescope.