The RCW 120 bubble seen by ESA’s Herschel space observatory. It lies about 4300 light-years away.
A star at the centre, not visible at these infrared wavelengths, has blown a beautiful bubble around itself with the mighty pressure of the light it radiates. The pressure is so strong that it has compressed the material at the edge of the bubble, causing it to collapse and triggering the birth of new stars.
The image is a composite of the wavelengths of 70 microns (blue), 160 microns (green) and 350 microns (red).