Complex flows of cold gas are shedding light on stellar nurseries: 'They're just these giant bridges of material'

Astronomers have observed flows of cold gas feeding the formation of stars in a multiple-protostar system.

Astronomers at the RIKEN Star and Planet Formation Laboratory have found out that gas flows fall onto two of three protostars in a stellar nursery located about 450 light-years away. The discovery has led to the belief that the processes that govern the formation of stars is in such nurseries. It is within the clouds of gas and dust that the stars are born. Multiple-protostellar systems are particularly fascinating for Nadia Murillo Mejias, a researcher at the RIKEN laboratory. She notes that multiple stars are responsible for some of the most intriguing phenomena in the universe, ranging from binary black holes to cataclysmic variable stars.

Despite their significance, there is still much that we do not know about multiple-protostellar systems. One critical question that remains unanswered is whether gas from the cloud flows evenly onto developing protostars or whether some receive more than others. This question is crucial since an uneven distribution of material would impact the evolution of multiple-protostellar systems. Murillo Mejias and her colleagues have discovered strong evidence that gas flows unevenly onto protostars in such systems. Specifically, they found that cold gas, just 10 to 30 degrees Celsius above absolute zero, is flowing onto a pair of protostars in the three-protostar system but not onto the third one.

Despite having been extensively studied in the past, this was the first time that such gas flows had been observed. "It was really interesting to see these extended structures of cold gas," says Murillo Mejias. "I mean their size is incredible; they're just these giant bridges of material." The team could observe the gas flows because they looked over a broader range of frequency bands than before. Still, the discovery had an element of serendipity. "The bandwidth we observed included the spectral lines of two key molecules in the structures," explains Murillo Mejias. "And so it was a bit of luck that we got to see them."

The elongated gas flows are very similar to onion-like structures. "We observed the gas flows for several molecules, and it turns out they're not tracing the exact same structure—they're offset from each other, like rings in an onion," says Murillo Mejias. The team is unsure of what's giving rise to this internal structure. "It's really interesting. It could be a chemical effect or something else," she says. "I think it's opening another door to discover what's happening there."

The team is now performing more observations on the multiple-protostellar system but on a much-expanded scale than before and is interested in seeing if other systems have similar gas flows. Their findings could affect our understanding of how stars form and evolve within multiple-protostellar systems. This discovery is a testament to the importance of continued astronomical research and the exploration of the mysteries of the universe. Murillo Mejias and her colleagues have made a significant contribution to our understanding of the processes that govern the formation of stars, and their work will undoubtedly inspire future research in this field.