For the first time, astronomers have examined molecular clouds in which systems of two, three, and even five stars are forming.

For the first time, astronomers have examined molecular clouds in which systems of two, three, and even five stars are forming.

Scientists have begun analyzing molecular cloud data collected by ALMA Radio Observatory. They then published their first results, an analysis of a large star-forming region. For the first time, systems containing different numbers of giant objects have been observed to form simultaneously. According to astronomers, most star systems have two, three, or more stars living next to each other. The exact ratio depends on the size of the star. Therefore, about half of all Sun-like luminous bodies have a companion star, but for stars eight times larger than the Sun, this number reaches 80%. The question is: do these systems form this way, or do they form when stars happen to come close together? Computer simulations show that the collapse of molecular clouds often forms systems with many massive stars. But so far, astronomers have discovered only a few massive protostar systems within the cloud. Furthermore, we could only reliably see systems with two stars, but not those with many companions.

The problem is that the dense, cold gas that dominates these clouds makes it extremely difficult to study star-forming regions in detail. The ALMA radio observatory consists of 66 antennas that provide these functions. The huge complex in the middle of Chile’s Atacama Desert became fully operational in 2013. From 2016 to 2019, a group of astronomers used ALMA to collect data on 30 promising star-forming regions. Scientists say they received about 800 gigabytes of data during each observation session. Therefore, it took years to analyze and compare images from different antennas within the complex. However, as a result, the researchers obtained images of an area of ​​​​200,000 astronomical units with an accuracy of up to 200 astronomical units. They first analyzed the star-forming region G333.23-0.06, about 17,000 light-years (5.2 kiloparsecs) away. Four systems of two protostars and one system of three, four, and five protostars were discovered. The results of the research were published in the journal “Nature Astronomy”.

source: https://www.nature.com/articles/s41550-023-02181-9