A team of astronomers has discovered seven Earth-sized planets orbiting a single dwarf star, Trappist-1. Although researchers believe that all the seven exoplanets could support life, only three are within the conventional “habitable” zone, reported BBC. Trappist-1 is located 40 light years away from the Earth.

“This is the first time so many planets of this kind are found around the same star,” Michael Gillon, an astronomer at the University of Liege in Belgium and the leader of the international team that has been observing Trappist-1, told Nature.

The study, which was published in the journal on Wednesday, also reveals that the exoplanets were detected using Nasa’s Spitzer Space Telescope and several observatories. However Trappist-1 is not like the sun. Its mass is one-twelfth of the sun and its surface temperature is a lot cooler.

Of the seven exoplanets, the fourth, fifth and sixth are in the “habitable zone”. However, scientists now need to study the atmospheres of these exoplanets to determine if they could support life. “It would be disappointing if Earth represents the only template for habitability in the Universe,” study co-author Amaury Triaud told BBC.

Last year, astronomers had found three exoplanets around Trappist-1. Now, the count has gone up to seven, reported AP. Astronomers are hopeful that they will find more planetary systems like that around Trappist-1 in the coming years.