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Repaired Hubble showcases Southern Pinwheel
Posted: November 05, 2009

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The sharp vision of Hubble's new Wide Field Camera 3 (WFC3) has captured swarms of young stars bursting into life in the curving arms of nearby spiral galaxy M83.

A close up view of the myriad stars near M83's bright, white core at right, with a ground-based view of the whole galaxy as seen by the European Southern Observatory’s Wide Field Imager on the ESO/MPG 2.2-metre telescope at La Silla, Chile, for context. The white box outlines Hubble’s view. Image: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

Known as the Southern Pinwheel galaxy, M83 also cocoons rapid star formation within its nucleus – spawning stars at a faster rate than in our own Milky Way Galaxy. This cauldron of star birth appears as the bright white region in the close up view of the galaxy's core.

Thanks to WFC3's broad wavelength range from ultraviolet to near-infrared, the image also picks out older generations of stars, including ancient hordes of globular star clusters and hundreds of thousands of individual stars – mostly blue and red supergiants.

Close up view of star formation in the M83's arms and core. Image: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

The unprecedented detail of the new image has allowed astronomers to probe deeper into the evolutionary history of star formation in this classic spiral galaxy than ever before. The newest generations of stars appear to be forming in clusters on the edges of the dark dust lanes, the backbone of the spiral arms. These stars are only a few million years old, their youthfulness betrayed by the bubbles of glowing red hydrogen gas surrounding them. Over time, radiation flung out from the newborns blows away the gas, revealing bright blue star clusters that are between one and ten million years old.

A bar of stars, gas, and dust slicing across the core of the galaxy may be funneling material to the galaxy’s centre where most of the star birth is occurring.

WFC3 also tracked down the remnants of some 60 supernova blasts – five times more than known previously in this region. Supernova explosions mark the end of a star's life, and by studying them, astronomers can gain insight into the nature of the progenitor star, which is responsible for the creation and dispersal of most of the galaxy’s heavy elements.

M83 is located 15 million light-years away in the southern constellation Hydra.