The constellation of Orion is a hotbed of massive star formation, most prominently in the Great Nebula that sits in Orion's sword.

The glowing gas of the Nebula is powered by a group of young massive stars, but behind it is a cluster of younger stars and clumps of gas. Still gathering together under gravity's pull, these gas clumps will eventually ignite into stars.

The movie shows that massive stars form like their smaller siblings, with disk accretion and magnetic fields playing crucial roles.

The way that massive stars form remains mysterious, in part, because massive stars are rare and tend to spend their youth enshrouded by dust and gas hiding them from view.

"We know how these stars die, but not how they are born," said Lincoln Greenhill, a principal investigator of the study and part of a team comprising scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) and the National Radio Astronomy Observatory (NRAO).

Unlike Hubble and other visible-light telescopes, radio telescopes can penetrate dusty veils around stars. The research astronomers studied a massive young protostar called Source I (pronounced "eye") at radio wavelengths, using the National Science Foundation's Very Long Baseline Array (VLBA) as a powerful "zoom lens."

The VLBA yielded even sharper images than the famous Hubble photos of "proplyds," or protoplanetary disks in Orion. The team observed Source I at monthly intervals over two years and then assembled the individual images into a time-lapse movie.

The VLBA detected thousands of silicon monoxide gas clouds called masers - naturally occurring laser-like beacons often associated with star formation. Some masers were as close to the protostar as Jupiter is to our Sun, which is also a record. Many of the masers existed long enough for their motions to be tracked across the sky and along our line of sight, yielding their 3-d motions through space.

"Artist's conception of the "boiling disk" surrounding the massive young stellar object known as Orion Source I. A disk of hot, ionized gas surrounds the central star, blocking our view. A cool wind of gas is driven from the upper and lower surfaces of the disk (as indicated by the colored arrows) and is sculpted into an hourglass shape by tangled magnetic field lines (shown as thin blue lines)."

"This outflow is lit up by emission from silicon monoxide molecules - emission that has been imaged and tracked by radio astronomers month-to-month. The entire disk and wind are rotating, leading to observable Doppler shifts of the material entrained in the wind; redder colors represent material with a component of motion away from the observer (into the plane of the sky), while bluer colors represent material moving toward the observer (out of the plane of the sky). (Credit: Bill Saxton, NRAO/AUI/NSF)"

Source: Harvard-Smithsonian Center for Astrophysics