October 2, 2007—This diamond-sharp Hubble Space Telescope image of some of the Milky Way's biggest stars shows a stellar nursery surrounded by a vast region of dust and gas.

Inside the NGC 3603 nebula, the stars run the gamut in age and mass—allowing scientists to analyze stars in different stages of their life cycles.

Released today, the new image suggests NGC 3603, which is about 20,000 light-years away, gathers its biggest stars at its core. It also shows that the nebula's dense distribution of stars mirrors other young clusters in the Milky Way, Jesús Maíz Apellániz, leader of the Hubble investigation, said in a statement.

The brightest stars in the image appear blue. Ultraviolet radiation and violent winds from these stars have created a large cavity in the reddish debris enveloping the cluster.

The nebula, discovered by Sir John Herschel in 1834, contains about 400,000 solar masses of gas.

A few Bok globules—dark clouds of dense dust and gas that are 10 to 50 times larger than the sun—also lurk in NGC 3603's swirling mass (visible as tiny black splotches at top right).

The globules are some of the coldest objects in the universe.

—Christine Dell'Amore

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