The M 17 region

Based on a large observational effort with different telescopes and instruments, mostly from the European Southern Observatory (ESO), a team of European astronomers [1] has shown that in the M 17 nebula a high mass star [2] forms via accretion through a circumstellar disc, i.e. through the same channel as low-mass stars.

To reach this conclusion, the astronomers used very sensitive infrared instruments to penetrate the south-western molecular cloud of M 17 so that faint emission from gas heated up by a cluster of massive stars, partly located behind the molecular cloud, could be detected through the dust.

Against the background of this hot region a large opaque silhouette, which resembles a flared disc seen nearly edge-on, is found to be associated with an hour-glass shaped reflection nebula. This system complies perfectly with a newly forming high-mass star surrounded by a huge accretion disc and accompanied by an energetic bipolar mass outflow.

The new observations corroborate recent theoretical calculations which claim that stars up to 40 times more massive than the Sun can be formed by the same processes that are active during the formation of stars of smaller masses.

ESO Press Video eso0416 zooms in towards the disc, starting from the ISAAC image of the full nebula to the NACO image of the silhouette disc. This shows the remarkable power of the set of instruments on the Very Large Telescope.