A new Earth-sized planet orbiting a small star that is likely 100 times brighter than the sun has been discovered by astronomers.

According to Nature Astronomy, this rocky planet, called Speculoos-3b, is 55 light-years from Earth and was spotted as it passed in front of its host star, an extremely cool red dwarf that produces half the heat of the sun but is 100 times brighter.

The newly discovered planet, described as “practically the same size as our own,” orbits the red dwarf once every 17 hours, making its time on the planet less than an Earth day.

But while the years are few for Speculoos-3b, the days and nights never end. “We believe that the planet rotates at the same time, so that the same side, called the day side, always faces the star, just as the moon does with the Earth. On the other hand, the night side is locked in endless darkness,” said Michaël Gillon, an astronomer at the University of Liege in Belgium and lead author of the study.

It is only the second planetary system discovered around such a star, following the detection of seven rocky worlds around Trappist-1, another cool red dwarf star 40 light-years from Earth.

Researchers spotted the planet as it wandered across the face of its star, causing a blur in the starlight. The transit was spotted by the Speculoos global network of robotic telescopes.

Extremely cool red dwarf stars make up about 70% of the stars in our galaxy and survive for about 100 billion years, making them the last stars left to shine in the universe. Because they are so faint and scattered across the sky, astronomers must observe them for several weeks to detect planets passing in front of them.

“In such an environment, the presence of an atmosphere around the planet is extremely unlikely,” said Julien de Wit, a planetary scientist at MIT and co-director of the Northern Speculoos Observatory and the Artemis telescope.