'Disk fragmentation behind binary-star formation'
Nearly half of all sun-like stars are members of double or multiple-star systems but till date, astronomers were debating how such systems are formed.
Now, a new research gives a boost to binary-star formation. Using the new capabilities of the upgraded Karl G. Jansky Very Large Array (VLA) near Magdalena, New Mexico, scientists have discovered previously-unseen binary companions to a pair of very young protostars.
"The only way to resolve the debate is to observe very young stellar systems and catch them in the act of formation. We have got valuable clues from them," said John Tobin of the National Radio Astronomy Observatory (NRAO).
According to the new study, 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, said the study published in Astrophysical Journal.
"The new findings, combined with the earlier data, make disk fragmentation the strongest explanation for how close multiple star systems are formed," claimed the study.
"The increased sensitivity of the VLA, produced by a decade-long upgrade project completed in 2012, made the new discovery possible," it added.
A binary star is a star system consisting of two stars orbiting around their common centre of mass.
The new capability was particularly valuable at the VLA's highest frequency band, from 40-50 GHz, where dust in the disks surrounding young stars emits radio waves.
The astronomers observed the young stars with the VLA and with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) in California.
(Posted on 01-01-2014)