Ground-breaking observations have been reported by an international team of astronomers, who is the first to witness the formation of a multiple-star system in its earliest stage. Their findings help support one of several proposed mechanisms by which scientists think these multistar systems might form.
Professor Stella Offner of the University of Massachusetts, and colleagues made the discovery while studying a dense core of gas called Barnard 5, located in a young star-forming region of the constellation Perseus, 800 light-years from Earth.
The authors were mapping radio emissions from methane molecules near a young proto-star when they detected fragmenting filaments of gas condensing to form three new stars.
“These kind of multi-star systems are quite common in the universe,” said Gary Fuller, a professor at the Jodrell Bank Center for Astrophysics, The University of Manchester. “Think of Tatooine in Star Wars, where there are two ‘suns’ in the sky. That isn’t too far away from something that could be a real formation. In fact nearly half of all stars are in this type of system.”
“Seeing such a multiple star system in its early stages of formation has been a longstanding challenge, 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,” said Jaime Pineda, of the Institute for Astronomy, ETH Zurich, in Switzerland.
In the present, the distances between these three gas condensations are massive, multiple times the size of our solar system, but the authors predict that, based on the strong gravitational attraction which exists between the, the stars will eventually come together to form a quadruple star system (including the young star in their vicinity). However, astronomers believe that, in less than a million years, one of the stars will be expelled due to increasing interactions between them, leaving a triple system.
“It seems like a simple question,” said Stella Offner. “Why is our sun a single star while the nearest star to us, Alpha Centauri, happens to be a triple system? There are competing models for how multiple star systems are born, but now we know a little more than we did before.”
“In terms of what this means for the formation of our sun,” she added, “it suggests that its early conditions did not look like this forming system. Instead, the sun likely formed from something that was more spherical than filamentary. The distribution of the planets in our solar system also suggests that our sun was never part of a multiple system like this one.”
Press release: https://goo.gl/IRX68V.