ALMA | ESO | NAOJ | NRAO | CfA | 2023 Jan 12
Scientists used the unique hydrogen radio recombination lines on MWC 349A to reveal hidden collimated jets.
While using the Atacama Large Millimeter/submillimeter Array (ALMA) to study the masers around oddball star MWC 349A scientists discovered something unexpected: a previously unseen jet of material launching from the star’s gas disk at impossibly high speeds. What’s more, they believe the jet is caused by strong magnetic forces surrounding the star. The discovery could help researchers to understand the nature and evolution of massive stars and how hydrogen masers are formed in space. ...
Located roughly 3,900 light-years away from Earth in the constellation Cygnus, MWC 349A’s unique features make it a hot spot for scientific research in optical, infrared, and radio wavelengths. The massive star— roughly 30 times the mass of the Sun— is one of the brightest radio sources in the sky, and one of only a handful of objects known to have hydrogen masers. These masers amplify microwave radio emissions, making it easier to study processes that are typically too small to see. It is this unique feature that allowed scientists to map MWC 349A’s disk in detail for the first time. ...
The observed jet is ejecting material away from the star at a blistering 500 km per second. That’s akin to traveling the distance between San Diego, California and Phoenix, Arizona in the literal blink of an eye. According to researchers, it is probable that a jet moving this fast is being launched by a magnetic force. In the case of MWC 349A, that force could be a magnetohydrodynamic wind— a type of wind whose movement is dictated by the interplay between the star’s magnetic field and gases present in its surrounding disk. ...
