RCW 79 is seen in the southern Milky Way, 17,200 light-years from
Earth in the constellation Centaurus. The bubble is 70-light years in
diameter, and probably took about one million years to form from the
radiation and winds of hot young stars.
The balloon of gas and dust is an example of stimulated star formation.
Such stars are born when the hot bubble expands into the interstellar gas
and dust around it. RCW 79 has spawned at least two groups of new stars
along the edge of the large bubble. Some are visible inside the small bubble
in the lower left corner. Another group of baby stars appears near the opening
at the top.
NASA's Spitzer Space Telescope easily detects infrared light from the dust
particles in RCW 79. The young stars within RCW 79 radiate ultraviolet light
that excites molecules of dust within the bubble. This causes the dust grains
to emit infrared light that is detected by Spitzer and seen here as the extended
red features.