Hubble Gives Best Ever View of Southern Pinwheel Galaxy

By SPACE.com Staff

posted: 05 November 2009 11:27 am ET

: The image at right is Hubble's close-up view of the myriad stars near the galaxy's core, the bright whitish region at far right. An image of the entire galaxy, taken by the European Southern Observatory's Wide Field Imager on the ESO/MPG 2.2-meter telescope at La Silla, Chile, is shown at left. The white box outlines Hubble's view. Credit: NASA, ESA, R. O'Connell, B. Whitmore, M. Dopita, and the Wide Field Camera 3 Science Oversight Committee/European Southern Observatory

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.