Scientists working with the European Southern Observatorys (ESO) New Technology Telescope in Chile have captured a stunning image of the Swan Nebula, a glowing stellar nursery located in the constellation Sagittarius. The nebula which also masquerades as M17, the Omega nebula, the Horseshoe nebula and the Lobster nebula is a large star-forming region in the Milky Way galaxy.

This latest ESO image of the Swan Nebula is helping researchers study the formation of supermassive stars. High-mass stars are interesting to astronomers because they are thought to greatly affect the formation and behavior of galaxies.

Current theory holds that most stars form in large clouds of gas and dust. But while low-mass stars are common and relatively easy to spot, it is much harder to identify evolving high-mass stars in the giant molecular clouds in which they form.

In an attempt to gather critical information on evolving high-mass stars, Leonardo Testi and Leonardo Vanzi, both astronomers at the ESOs La Silla Observatory in Chile, have imaged M17 in near-infrared wavelengths. Because both high- and low-mass stars are impossible to see at visible wavelengths when they are young, infrared imagery can more clearly capture the different star-mass types located in this nebula.

One key question astronomers hope to find out by studying objects like the Swan Nebula is whether high-mass stars form by gradual accretion of gas in nebular clouds, or by stellar collisions in dense clusters. And although experts will have to also study globular star clusters to find out, images such as the latest from the New Technology Telescope will be of great help in the quest to understand supermassive star formation.