Right now our understanding of solar system formation is more of an illustrated picture book than a complete documentary movie. We have snapshots of understanding, but the details are sketchy. We are filling in details over time.
In a new paper in Nature Astronomy, a team led by Jaime Pineda describes how young stars fed on an infalling stream of material that stretched 10,500 AU in length. This distance is roughly 350 times greater than the distance to Neptune or Pluto. In this system, IRAS 03292+3039, a binary system is forming at the center of a rich disk of material. Over time, these stars would deplete the disk if there wasn’t new material continuing to flow in from the surrounding molecular cloud.
While we’ve understood this process for a long time, the inflow of material hadn’t been directly seen until now. Using the IRAM telescope, which works in millimeter wavelengths of light, they were able to map the flow of material in the Perseus Molecular Cloud in high enough resolution to see how material flowed from the surrounding cloud into the forming binary system. They looked at the light from three specific molecules, detailing how different material is flowing, and they estimated that between 0.1 and 1 solar mass is in the stream. According to Pineda: The streamer must indeed bring in chemically fresh material from the outer regions on a relatively short timescale. The clear identification of such a large reservoir of fresh material in almost free-fall is remarkable.
The streamer may represent a single moment in time and may not be a long term feature or even a common feature. More observations of more star-forming systems are needed, but at least now we know these kinds of features can exist and play a role in feeding young solar systems.
“A Protostellar System Fed by a Streamer of 10,500 AU Length,” Jaime E. Pineda, Dominique Segura-Cox, Paola Caselli et al., 2020 July 27, Nature Astronomy