Fountains of spewing gas provide look at megastar formation

Dramatic changes around a young, massive star are giving astronomers a rare real-time look at how these stellar behemoths develop. Images taken 18 years apart show an eruption of gas streaming away from the star’s poles, researchers report  in the April 3 Science.

Radio telescope images taken in 1996 showed a growing bubble of gas forming around the star, which is about 4,200 light-years away in the constellation Cygnus. The same gas is now spewing out in two opposite directions, data obtained in 2014 show. The star belched out a wave of gas that subsequently ran into a doughnut of dust surrounding the star, suggest Carlos Carrasco-González, an astrophysicist at the National Autonomous University of Mexico in Morelia, and colleagues. The wall of dust slowed down some of the gas while the rest burst out above and below the disk.

The outburst could become far-reaching jets of gas such as those frequently seen around young stars that are much less massive (SN: 10/5/13, p. 12). Researchers expect these jets to erupt from massive stars as well, but generally find only amorphous blobs of gas oozing in all directions. These before-and-after images can help astronomers understand how stellar winds, gas and the surrounding environment all interact to build a new massive star.