Astronomers discover ‘impossible’ exoplanet orbiting low-mass star
Astronomers have made a groundbreaking discovery that challenges current theories of planet formation. The planet, named LHS 3154b, was found orbiting an ultracool M-dwarf star called LHS 3154, which is nine times less massive than our sun. It is the most massive known planet in a close orbit around one of the coldest, low-mass stars in the universe.
The discovery, detailed in a study published Thursday in the journal Science, has left scientists questioning their understanding of how planets and stars form. The planet’s existence is raising new questions about how planetary systems can evolve.
“This discovery really drives home the point of just how little we know about the universe,” said study coauthor Suvrath Mahadevan, an astronomy and astrophysics professor at Penn State.
According to current theories, the planet-forming disk around the low-mass star LHS 3154 should not have had enough solid mass to create a planet as heavy as LHS 3154b. This finding has the potential to reshape scientists’ understanding of planetary formation and the role of low-mass stars in the process.
LHS 3154b orbits its star at a close distance, completing one orbit every 3.7 Earth days, surprising astronomers who expected small, rocky planets rather than gas giants to orbit small M-dwarf stars.
The discovery was made using the Habitable Zone Planet Finder (HPF) installed on the Hobby-Eberly Telescope at the McDonald Observatory in Texas. The HPF was specifically designed to detect planets orbiting small, cool stars within the habitable zone where liquid water on the surface could potentially support life.
This finding provides an extreme test case for existing planet formation theories and highlights the need for further exploration of low-mass stars and their relationships with planetary systems.