Scientists at the Max Planck Institute for Extraterrestrial Physics have demonstrated that stars can be born by receiving matter from outside their parent molecular cloud. The research results, published in the journal Astronomy & Astrophysics, reconsider conventional wisdom about the formation of stars and planets.

Astrophysicists have studied the role of streamers and filaments, which are streams of material that extend over distances of up to 10,000 astronomical units, or 0.15 light years. Observations of molecular clouds in the Barnard 5 Nebula were made with the ALMA radio interferometer in Chile and other instruments. One of the protostars in this cloud has two neighboring filament structures. According to current theory, star formation occurs in cold molecular clouds, also known as stellar nurseries. Material begins to accumulate in part of the cloud, consisting mainly of hydrogen. Slow gravitational collapse occurs, forming a dense region in the cloud that emits light. It continues to grow, attracting more and more matter until nuclear fusion begins.

The results show that jets transport fresh gas from the nebula to the protostar’s embryonic envelope, penetrating directly into the surrounding disk. Streams and filaments therefore appear to be an integral part of the star formation process, as they supply material from other parts of the nebula. Streams of fresh gas in the parent cloud affect not only the stars, but also future planets. Planets form from material in the protostellar disk and will have the chemical imprint of other parts of the nebula where the streamers come from. This substance is not affected by the temperature, pressure and magnetic environment of the stellar nurseries themselves.

source: https://dx.doi.org/10.1051/0004-6361/202346357