Amazing Discovery: ALMA Detects Multiple-Star System Giving Birth to 3 Stars

Data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile provides first direct glimpse of the development of a multiple-star system.

The discovery, described in a paper published in the journal Nature, showed the formation of two young stars in the whirling disk of gas surrounding the older stars. This discovery supports the theory stating that the circumstellar disk, or the gas and dust whirling around a forming star, could split up and form orbiting companion star, giving birth to a multiple-star system.

"This new work directly supports the conclusion that there are two mechanisms that produce multiple star systems -- fragmentation of circumstellar disks, such as we see here, and fragmentation of the larger cloud of gas and dust from which young stars are formed," explained lead author John Tobin, of the University of Oklahoma and Leiden Observatory in the Netherlands, in a press release.

The new multiple-star system, dubbed as L1448 IRS3B, is located in the constellation Perseus, about 750 light years away from Earth. The researchers estimate the whole system to be less than 150,000 years old, with the farthest star to be only 10,000 to 20,000 years old.

Using ALMA, together with data from the Very Large Array (VLA) in New Mexico, the researchers were able to measure the distance between the stars. The inner young star orbiting the oldest central star is about 61-times the distance of Earth from the sun. On the other hand, the outermost star is approximately 183 times the Earth-Sun distance. All the three stars appear to be surrounded by a disk of material forming a spiral structure. The structure of the star system indicates the instability of the disk surrounding the stars.

With the discovery of the L1448 IRS3B, astronomers now have direct observational evidence that fragmentation in the disk can produce young multiple-stars system very early in their development.

At present, about half of all the known stars belong to a binary star system, a kind of multiple-star system where two stars orbits one another.