An international team of astronomers and astrophysicists has confirmed the first known observation of a tidally locked super-Earth exoplanet. In his article published in the magazine Astrophysical JournalThe team describes the unique approach they took to confirm that exoplanet LHS 3844b is tidally locked, and that this finding points to other planets in the galaxy.

Previous research had led astronomers to believe that some exoplanets were tidally locked, with one side always facing the star they orbit, but so far they have not been able to prove this. In this new study, the research team selected a likely candidate and used a unique approach to study its properties to determine its movement.

Previous studies have shown that several moons in our solar system, including the one orbiting Earth, are tidally locked and always face the planet they orbit. In this case, the rotation periods coincide with the orbital periods; The result is a moon that always points in the same direction to its planet. Therefore, Earth’s moon has the side we never see, often called the “dark side.” Tidal obstruction occurs due to gravitational forces between the moon and its planet or the planet and its star.

To test whether super-Earth exoplanet LHS 3844b is tidally locked, researchers examined infrared data from the Spitzer Space Telescope to measure the amount of starlight the planet reflects. This allowed the team to calculate the planet’s surface temperature. By doing this at different points in the star’s orbit, the team was able to detect that one side of the planet was much colder than the other; this difference was large enough to indicate that the cold side never made contact with the star.

Researchers argue that the discovery of a tidally locked planet strongly indicates that there are many more out there. Some in the field suggest that many planets in the Milky Way galaxy are likely tidally locked. If so, the researchers suggest some may contain life at the hot-cold boundary.