Westerlund 2 (Detail)

Westerlund 2 is surrounded by the star-forming region Gum 29. The heaviest cluster stars are unleashing a torrent of ultraviolet radiation and hurricane-force winds streaming with charged particles, etching away the enveloping hydrogen gas cloud from where the cluster formed. The nebula reveals a fantasy landscape of pillars, ridges, valleys, and reddish-brown filaments of dense gas and dust. The brightest stars in the image are Milky Way foreground stars not associated with Westerlund 2.

The pillars in the star-forming region surrounding Westerlund 2, composed of dense gas, are a few light-years tall and point to the central cluster. They are thought to be incubators for new stars. Besides sculpting the gaseous terrain, intense radiation from the most brilliant of the cluster stars is creating a successive generation of baby stars. The bluish haze is an indicator of oxygen gas in the nebula.

Release Date: April 23, 2015

Credit: NASAESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team