New Star System Supports Binary-Star Formation Theory

Scientists have made a new discovery using the Karl G. Jansky Very Large Array (VLA). They've found a previously-unseen binary companions to a pair of very young protostars. The new discovery gives strong support for one of the competing explanations for how double-star systems form.

Astronomers know that about half of all sun-like stars are members of double or multiple-star systems. Yet they've debated for years about how these systems are formed. The only way to resolve this debate is to observe very young stellar systems and catch them in the act of formation. That's why the scientists took a closer look at this particular star system.

So what did the researchers find by examining this star system? The new clues they've uncovered support the idea that double-star systems form when a disk of gas and dust whirling around one young star fragments, forming another new star in orbit with the first. Young stars that still are gathering matter from their surroundings form such disks, along with jet-like outflows rapidly propelling material in narrow beams perpendicular to the disk.

"This fits the theoretical model of companions forming from fragmentation in the disk," said John Tobin, one of the researchers, in a news release. "This configuration would nto be required by alternative explanations."

The findings help support the disk-fragmentation theory. In fact, combined with earlier data, this theory is the strongest explanation for how close multiple star systems are formed. With further studies, astronomers hope to confirm this theory in the future.