Galaxies in the background universe

The giant nebula NGC 3603 discovered by John Herschel in 1834, houses in it, thousands of sparkling young stars. This magnificent panorama is one of the star more massive young star clusters in the Milky Way.
NGC 3603 is a nursery of active star formation, located in the Carina arm of our Galaxy, about 20 000 light years from our solar system. The image against the Hubble Space Telescope shows an impressive young star cluster surrounded by a vast region of dust and gas. The intense ultraviolet radiation and solar winds of the stars bluer and hotter swelled a big bubble around the cluster. The shift in the wind nebula of radiation, formed large dark areas in the nebula.
These soft areas that span multiple light years, are oriented toward the center of the cluster.
Dark clouds are observed in clusters, called Bok globules a Bok globule is a cluster of dark dust and gas of the interstellar medium, in which, may start the thermonuclear reactions of newborn stars. , visible in the upper right corner.
These clouds are composed of dense dust and gas and are about 10 to 50 times more massive than the Sun.
A Bok globule may undergo a gravitational collapse and lead to the formation of new stars. Bathed in gas and dust of the cluster, hot stars (blue in the image), are responsible for the enormous cavity in the gas to the right of the star clusters in the center of NGC 3603.

NB: A Bok globule is a cluster of dark dust and gas of the interstellar medium, in which, may start the thermonuclear reactions of newborn stars.

Image: A nursery of active stars in the nebula NGC 3603 (shooting Hubble Space Observatory). Most of the stars of this picture, are very hot young stars, visible in blue. They emit ultraviolet radiation and violent winds that dig holes in the range of gas and dust around them. The image covers approximately 17 light years and was completed December 29, 2005 with the instrument ACS (Advanced Camera for Surveys).
Hubble images of high resolution ESA.