A study recently published in the journal Nature reveals the discovery and the first-ever observations of a multiple-star system during the earliest stage of formation, supporting one of several suggested mechanisms to the production of such systems.
Researchers of the study, led by Jaime Pineda of the Institute for Astronomy (ETH Zurich) in Switzerland, discovered the quadruple star system by studying a dense core of gas called Barnard 5 (B5) in the “stellar nursery” region of the constellation Perseus. The core contained one young protostar and three dense condensations that are expected to form into stars in approximately 40,000 years, a relatively short timeframe in astronomical terms.
“We know that these stars eventually will form a multi-star system because our observations show that these gas condensations are gravitationally bound,” said Pineda in a recent statement. “This is the first time we’ve been able to show that such a young system is gravitationally bound.”
The team found that filaments of gas in B5 are fragmenting, and the fragments are starting to form into additional stars that will lead to a multiple-star system.
“This provides fantastic evidence that fragmentation of gas filaments is a process that can produce multiple-star systems,” said Pineda. Other theories include fragmentation of the main gas core, fragmentation within a disk of material orbiting a young star, and gravitational capture. “We’ve now convincingly added fragmentation of gas filaments to this list.”
The team used observations made by the Very Large Array (VLA), an astronomical radio observatory in New Mexico, and the Green Bank Telescope (GBT), the world’s largest fully steerable radio telescope in West Virginia, to make their discovery.
“Nearly half of all stars are in multiple systems, but catching such systems at the very early stages of formation has been challenging. Thanks to the combination of the VLA and the GBT, we now have some important new insight into how multiple systems form,” said Pineda. “Our next step will be to look at other star-forming regions using the new capabilities of the VLA and of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.”