NRAO: The Unfolding Saga of Massive Star Formation

[bystander]

Astronomers Watch Unfolding Saga of Massive Star Formation
National Radio Astronomy Observatory | 2015 Apr 02

[i]Artist's conception of the development of W75N(B)-VLA-2.. At left, a hot wind from the young star expands nearly spherically, as seen in 1996. At right, as seen in 2014, the hot wind has been shaped by encountering a dusty, donut-shaped torus around the star and appears elongated. [b](Credit: Bill Saxton, NRAO/AUI/NSF)[/b][/i]

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A pair of images of a young star, made 18 years apart, has revealed a dramatic difference that is providing astronomers with a unique, "real-time" look at how massive stars develop in the earliest stages of their formation.

The astronomers used the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to study a massive young star called W75N(B)-VLA 2, some 4200 light-years from Earth. They compared an image made in 2014 with an earlier VLA image from 1996.

"The comparison is remarkable," said Carlos Carrasco-Gonzalez of the Center of Radioastronomy and Astrophysics of the National Autonomous University of Mexico, leader of the research team. The 1996 image shows a compact region of a hot, ionized wind ejected from the young star. The 2014 image shows that ejected wind deformed into an distinctly elongated outflow.

"We're seeing this dramatic change in real time, so this object is providing us an exciting opportunity to watch over the next few years as a very young star goes through the early stages of its formation," Carrasco-Gonzalez said. ...

Observing the onset of outflow collimation in a massive protostar - C. Carrasco-González et al

• Science 348(6230) 114 (03 Apr 2015) DOI: 10.1126/science.aaa7216