Within the gorgeous Orion Nebula lies the open cluster of stars known as Trapezium. The powerful stellar winds of these objects have created a shell of dust and gas with a thickness of one light-year known as the Orion Veil – but this spherical shell is being pierced.
As reported in Astronomy & Astrophysics, the team discovered a protrusion moving at about 12 kilometers (7.5 miles) per second, and they believe that the properties of said protrusion will allow it to pierce through the Orion Veil.
“The bubble – with a diameter of approximately seven light-years – should be an almost sphere-like structure, but we found a protrusion in its northwestern part,” Ümit Kavak, a postdoctoral researcher at SOFIA based out of NASA’s Ames Research Center in California, said in a statement.
SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a telescope installed on a plane, as traveling higher in the atmosphere can deliver better-infrared observations. In this case, the team tracked the emission of carbon atoms throughout the protrusion. The astronomers could tell its size, how it is expanding, and its overall structure.
The protrusion is like a "U" lying on its side. This chimney-like top suggests that it might have already pierced the Orion Veil. If it hasn’t, it is likely very close to doing that.
“When you breach the Veil shell, you effectively start stirring a cosmic soup of gas and dust by adding turbulence,” Kavak said.
“This isn't the most appetizing soup, but it's one of the ways to form new stars or limit future star formation,” added Alexander Tielens, a researcher at Leiden University and a co-author of the paper.
The cause of the protrusion is not certain – but the team has some solid hypotheses, and they are all about the young stars within the Trapezium. The protrusion might have been formed from jets and outflow of stars about to form, or it might be preexistent clumpiness of material being given a kick. Or, just another effect of the stellar winds.
Based on the current observations, the team believes that the protostars as they come to life are the cause of the protrusion, and the team thinks the interaction between protostellar jets and established stellar winds can be very important in the evolution of these stellar environments.
"Because this star cluster (Trapezium cluster) is found in the nearest massive star-forming region, we study its dynamics and kinematics of a massive star-forming region in greater detail than other massive star-forming regions in the Galaxy. This region has been the source of many important discoveries about ISM [interstellar medium] dynamics and massive star formation," Dr Kavak told IFLScience.
The Trapezium cluster is located 1350.2 light-years away.