Multiple star system seen forming

Scientists discover a nascent multiple star system for the first time

Barnard 5, where the nascent multiple star system has been spotted, is around 800 lightyears from Earth. Image Credit: NRAO/AUI/NSF
Published: February 11, 2015 at 12:00 pm
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An international team of scientists has managed, for the first time ever, to catch a multiple star system in the process of formation.


The team - led by Jaime Pineda of Switzerland's Institute of Astronomy, ETH Zurich, and comprising astronomers from the University of Manchester, Liverpool John Moores University and other institutions - studied an area of star formation in the constellation of Perseus, using a number of ground-based telescopes, including the Very Large Array in New Mexico, USA, the Green Bank Telescope in West Virginia, USA and the James Clerk Maxwell Telescope, Hawaii.

Within the vast cloud of gas and dust, they identifed one particular region called Barnard 5, or B5, that is home not only to a young protostar, but also to three dense clouds of matter that will, according to the astronomers, collapse into stars over the next 40,000 years.

The team say that eventually a triple-star system will form, with one unlucky star likely to be ejected from the system.

The condensations in B5 that will produce stars range from one-tenth to more than one-third the mass of the Sun, and the stars that eventually form will be separated by between 3,000 and 11,000 times the Earth-Sun distance.

“Seeing such a multiple star system in its early stages of formation has been a longstanding challenge," said Professor Gary Fuller of the Jodrell Bank Centre for Astrophysics at the University of Manchester.

"But the combination of the Very Large Array (VLA) and the Green Bank Telescope (GBT) has given us the first look at such a young system.”

The real clue to this region's future, said team leader Jaime Pineda, came in VLA data that showed filaments of gas in B5 are fragmenting.

"We know that these stars eventually will form a multi-star system because our observations show that these gas condensations are gravitationally bound," he explained.

“This is the first time we’ve been able to show that such a young system is gravitationally bound, [and] provides fantastic evidence that fragmentation of gas filaments is a process that can produce multiple-star systems."

“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.


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,” Pineda said.


Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.


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