The Hubble Space Telescope's powerful new camera has taken
the most detailed image yet of star birth in the nearby spiral galaxy M83.
Nicknamed the Southern
Pinwheel, M83 is undergoing more rapid star formation than our own Milky
Way galaxy, especially in its nucleus.
In this galaxy, the sharp eye of the Hubble's Wide Field
Camera 3 (WFC3) — newly installed this summer during the telescope's fourth and
final servicing mission — has captured hundreds of young star clusters, ancient
swarms of globular star clusters, and hundreds of thousands of individual
stars, mostly blue supergiants and red supergiants.
WFC3's broad wavelength range, from ultraviolet to
near-infrared, reveals stars at different stages of evolution, allowing
astronomers to dissect the galaxy's star-formation history.
The new image reveals in unprecedented detail the current rapid
rate of star birth in this spiral galaxy. The newest generations of stars are
forming largely in clusters on the edges of the dark dust lanes, the backbone
of the spiral arms. These fledgling stars, only a few million years old, are
bursting out of their dusty cocoons and producing bubbles of reddish glowing
hydrogen gas.
Gradually, the young stars' fierce winds (streams of charged
particles) blow away the gas, revealing bright blue star clusters. These stars
are about 1 million to 10 million years old. The older populations of stars are
not as blue.
A bar of stars, gas, and dust slicing across the core of the
galaxy may be instigating most of the star birth in the galaxy's core. The bar
funnels material to the galaxy's center, where the most active star formation
is taking place. The brightest star clusters reside along an arc near the core.
The remains of about 60 supernova
blasts, the deaths of massive stars, can be seen in the image, five times
more than known previously in this region.
M83 is located 15 million light-years away in the Southern
Hemisphere constellation Hydra.
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