W51

W51 is a large star-forming complex in the Milky Way, seen in the direction of the constellation Aquila. It contains molecular clouds, ionized gas, and regions where massive stars are forming.

W51 is an active site of high-mass star formation. Studying it helps astronomers examine how very large stars form inside dense clouds of gas and dust.

The complex contains molecular clouds and ionized gas. These components trace both the cold material that feeds star formation and the energetic radiation from young massive stars.

Radio wavelengths can pass through much of the dust that hides young stars from visible-light telescopes. Astronomers therefore use radio observations to map gas and investigate activity inside the W51 complex.