What an 'eccentric' star in the Cygnus cluster can tell us about how masers are made

Like going to the store for dog food and returning with a duck, researchers at the National Radio Astronomy Observatory may have discovered significant insight into the formation of masers (nature's lasers) during a routine study of the "weird". “star MWC 349A using the Atacama Large Millimeter/submillimeter Array (ALMA). It appeared as a previously unseen jet of ejected material, launched away from the star at “incredibly high speeds,” according to the NRAO.

MWC 349A, which lies 3,900 light-years away in the constellation Cygnus, earned its odd nickname by being 30 times larger than our own star, as well as one of the brightest radio sources of the sky. It is also one of the only observed celestial objects known to have a hydrogen maser. These are as cool as they look, being radio wavelength analogs to lasers that emit strong, narrow beams of radiation instead of coherent light. Natural masers are valuable research tools because they amplify radio wave emissions, allowing researchers to study processes too distant or obscured to be seen visually - think star-sized megaphones in space.

"A maser is like a natural laser," Sirina Prasad, the study's lead author and undergraduate research assistant at the Center for Astrophysics, said in a statement Monday. "It's an area of ​​outer space that's emitting a kind of very bright light. We can see that light and trace it back to its origin, which brings us a little closer to understanding what's going on. actually happens.

The scientific community has known of the existence of MWC 349 since 1989 when they observed that it had "some of the characteristics of a molecular maser source: it was extremely bright and varied over time, a result of sensitivity to changes in detailed excitation processes," wrote Ignacio Diaz Bobillo of the Center for Astrophysics in 2013.

He notes that the maser source offered three great features:

The first is that the excited atoms produced a series of masers at a series of wavelengths from the corresponding set of hydrogen lines - some even at wavelengths short enough to be trumpeted as natural lasers. The second is that the many lines allowed scientists to model the emitting region in detail. It is a disk on the edge rotating in a so-called Keplerian way, that is to say like the planets orbiting in the solar system with those close to the Sun orbiting faster than those far from the Sun (very different of the rotation of a solid disc). The last mysterious point was that this first hydrogen maser source seemed to be unique.

No one understands why, but despite decades of searching for other hydrogen maser sources, only two other possible examples have been proposed, though they remain uncertain at best.

“Our previous understanding of MWC 349A was that the star was surrounded by a spinning disk and a photo-evaporating wind,” Prasad continued. "Strong evidence of an additional collimated jet had not yet been seen in this system." But that's what they stumbled upon this time.

The collimated jet is hurtling away from the star and its disc of gas at a blistering speed of 500 km/s. At these speeds, you can get from San Diego, California to Phoenix, Arizona faster than you can say "Please, no, anyway...