Astronomers may have just caught a glimpse of the early signs of the formation of “baby” solar systems in the hydrocarbon-rich disc around two young stars in a star-forming region near Earth, in a study that could offer fresh insights into how planetary systems are created. From studying 78 protoplanetary disks — or flattened clouds of gas and dust — in the Rho Ophiuchi cloud complex, researchers spotted spiral and ring-like substructures, which are certain signatures that baby planets are in the process of being born.
The disks, around stars a few hundred thousand years old showed unusual characteristics, indicating that planet and star formation are simultaneous processes in very young systems. In comparison, the Sun is a middle-aged 4.6 billion years old.
High-Res ALMA Imaging Reveals Planet Formation Begins Earlier in Young Star Disks Than Expected
As per the research team, the discovery helps bridge a key observational gap between previous ALMA studies—DSHARP, which focused on million-year-old stars, and eDisk, which studied much younger protostars. By targeting stars of intermediate ages and applying PRIISM super-resolution software to archival ALMA data, researchers achieved images three times sharper than standard methods. Their larger sample led to the identification of 27 disks with structures, including 15 never seen before.
The results indicate that substructures such as rings and spirals, believed to be the fingerprints of planet formation, appear much earlier in a planet’s growth process than previously thought, when the disks are still full of gas and dust. During the childhood of young stars forming in collapsed molecular clouds, these disks were born, and in the same way, young planets formed within the lifetimes of these accretion disks, moved, and shaped the objects in the disk.
Most disks observed were about 30 astronomical units wide, roughly 30 times the Earth-Sun distance. The presence of intricate structures in such early systems implies a parallel evolution of infant stars and planets. The research indicates that star and planet creation might be more closely linked than thought.
The research, which was published on an online site for The Publications of the Astronomical Society of Japan, was led by Ayumu Shoshi of Kyushu University. The present results involve only the Ophiuchus regions, but in the future, as more data become available, we will be able to search for similar early co-evolution amongst other stellar nurseries.