Thursday, August 12, 2010

SCIENCE - Hubble's NGC 4911 Spiral Galaxy


"Hubble Space Telescope: NASA's stunning new image of 'spiral galaxy'" by Andrew Hough, Telegraph UK 8/10/2010

The galaxy, titled NGC 4911, lies more than 320 million light-years away in the "Coma Cluster" of about 1,000 galaxies and islands of stars similar to the Milky Way.

NASA said the stunning long-exposure picture, titled “Island Universe”, shows the “majestic face-on spiral galaxy” in the northern constellation Coma Berenices amid a sea of stars.

The galaxy contains “rich lanes of dust and gas near its center” and is silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, which indicates ongoing star formation.

NASA scientists say the cluster is one of the densest collections of galaxies in a nearby universe and as a result this proximity means the galaxies often interact violently.

The "natural-color" image, released by the space agency combines data from 2006, 2007, and 2009. A high resolution copy of the image has also been released.

Using Hubble’s brand new Wide Field Planetary Camera 2 and the Advanced Camera for Surveys, it required 28 hours of exposure time.

The long wispy formations, seen along the “arms” of the main galaxy, are a result of the nearby galaxy passing "perilously close to each other".

“The high resolution of Hubble’s cameras, paired with considerably long exposures, made it possible to observe these faint details”, a NASA spokesman said.

“(The galaxy) and other spirals near the center of the cluster are being transformed by the gravitational tug of their neighbors.

“In the case … wispy arcs of the galaxy’s outer spiral arms are being pulled and distorted by forces from a companion galaxy.”

One light year is the equivalent of 5.9 trillion miles.

It is the latest in a series of spectacular images taken by the telescope and released by NASA.

In April Hubble celebrated its 20th anniversary with an image of a space constellation.

More than half a million pictures have been amassed in its extensive archive from about 30,000 space celestial targets.

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