ALMA Explores Deeper into the Enigma of Planet Formation

An international research team has used the Atacama Large Millimeter/submillimeter Array (ALMA) to study 19 protostars in order to search for early signs of planet formation. The team was motivated by recent findings that suggested planet formation may already be occurring in more evolved proto-planetary disks. However, there had not been a systematic study to investigate signs of planet formation in younger protostellar systems.

Planets form in disks around newborn stars, known as proto-planetary disks, which only last a few million years. This means that the formation of a planetary system must occur within this timeframe. However, it is still unclear how quickly planet formation begins within these disks.

Recent ALMA observations have shown that many proto-planetary disks have substructures such as gaps and rings, indicating that planets are already forming. This led the research team to investigate even younger disks around protostars to determine at what stage of star formation planet formation occurs.

The team observed disks around 19 protostars located within approximately 650 light-years from Earth. This study is the first to systematically investigate the detailed structure of disks around a large sample of protostars with high angular resolution. The observations revealed that the disks around protostars are different from more evolved proto-planetary disks. Among the 19 protostars, only a few showed signs of planet formation, such as rings and gaps. Additionally, the ring structures observed in the protostars were less distinct than those seen in the more evolved disks.

The researchers were surprised by the clear differences between the disks around protostars and more evolved disks. They suggest that the disks around protostars are not fully prepared for planet formation. Instead, they believe that the actual formation of a planetary system occurs rapidly within 100,000 to 1,000,000 years after star formation begins.

This study provides valuable insights into the early stages of planet formation and highlights the importance of studying protostellar systems to better understand the processes involved in the creation of planetary systems.