Astronomers have announced the discovery of TIDYE-1b, one of the youngest exoplanets ever found, which may significantly enhance understanding of early planet formation stages. At just 3 million years old, TIDYE-1b is a mere infant compared to Earth’s 4.5 billion years.
Madison Barber, lead author and graduate student at the University of North Carolina at Chapel Hill, identified TIDYE-1b using the transit method, where a planet passes in front of its star. While over a dozen young planets aged between 10 and 40 million years have been discovered, TIDYE-1b surpasses them in youth.
This discovery is rare, as such young planets are typically obscured by gas and dust in a protoplanetary disk—a debris field surrounding a star from which new planets form. However, TIDYE-1b orbits its star at an angle different from the primary protoplanetary disk, allowing it to be visible despite its youth.
Andrew Mann, an assistant professor at UNC-Chapel Hill, noted that typically, planets form from a flat disk of dust and gas, leading to a “pancake” shape in our Solar System. In this case, the disk is tilted, presenting a new perspective on planetary formation.
TIDYE-1b orbits its star every nine days and is thought to be a young example of what may evolve into a super-Earth or sub-Neptune—types of planets absent in our Solar System but common in the Milky Way. Although less dense than Earth, its diameter is approximately 11 times larger.
The discovery of TIDYE-1b provides compelling evidence that planets can form earlier than previously believed. The lack of examples younger than 10 million years was attributed not to their non-existence but to their typical obscurity. This finding may prompt a reevaluation of planet formation models and enhance understanding of the birth processes of planets in the universe.