Paris, France – Researchers using global robotic telescopes have made a groundbreaking discovery of an Earth-sized planet orbiting a long-lived red dwarf star within the Milky Way galaxy. This newly discovered planet, named SPECULOOS-3 b, offers valuable insights into potentially habitable worlds and sheds light on the characteristics of long-lived red dwarfs, which are expected to be among the last stars burning in the universe.
Within our galaxy, the Milky Way, red dwarf stars are abundant, with more than 70% of the stars belonging to the category of M dwarfs, commonly known as red dwarfs. Although these stars are cooler and dimmer compared to our Sun, they emit high-energy radiation that can impact orbiting exoplanets, especially in their early stages. Unlike our Sun, which burns for about 10 billion years before transitioning into a red giant, M dwarfs can continue burning for over 100 billion years, potentially providing a conducive environment for life to arise.
An international team of astronomers using robotic telescopes across the globe recently identified an Earth-sized planet revolving around an ultra-cool red dwarf star, the dimmest and most enduring type of star. These ultra-cool dwarf stars are widespread in our region of the galaxy, yet their planetary systems remain largely unexplored. The SPECULOOS project, spearheaded by Michael Gillon from the University of Liège, Belgium, aims to address this gap by focusing on nearby ultra-cool dwarf stars to search for rocky planets.
SPECULOOS-3 b, the Earth-sized exoplanet in question, is situated approximately 55 light-years away from Earth and orbits the red dwarf star in about 17 hours. Due to its likely tidal locking, one side of the planet always faces the star, leading to perpetual dayside and nightside conditions.
The red dwarf star hosting SPECULOOS-3 b is significantly cooler than our Sun, with an average temperature of around 4,760 F (2,627 C). Despite its dimness, the star bombards its planetary companion with radiation, raising questions about the presence of an atmosphere on the exoplanet.
Moving forward, SPECULOOS-3 b presents an enticing opportunity for further investigation using the James Webb Space Telescope. This next phase of exploration could provide valuable insights into the exoplanet’s atmospheric composition, surface characteristics, and broader implications for our understanding of neighboring stellar systems and our place within the universe.