May 19, 2010 at 9:00 AM ET
M. Gieles / ESO
The spiral galaxy Messier 83 is a delicate wisp in infrared wavelengths, as seen at
left by the HAWK-I instrument on the European Southern Observatory's Very Large
Telescope. But it looks like a fiery pinwheel in the visible-light image at right,
captured by the MPG/ESO telescope. Click on the picture for a larger view.
The spiral galaxy Messier 83, also known as the Pinwheel Galaxy, is a spectacular fireworks show when it’s seen through a big telescope in visible light. But when the European Southern Observatory looked at the pinwheel in infrared wavelengths, the result was a much more delicate, no less beautiful picture of the galaxy’s hottest young stars with the surrounding gas stripped away.
M83, which sits about 15 million light-years away from us in the constellation Hydra, isn't exactly an undiscovered treasure. It's one of the best-known galaxies, easily seen with binoculars or a small telescope. It's also one of the most photographed galaxies: Just last year, the Hubble Space Telescope's brand-new Wide Field Camera 3 gave it the full treatment, focusing in on bursts of starbirth within its big, bright spiral arms.
But just one telescope is never enough, even if it's Hubble. The latest view of M83, released today by the ESO, comes from the High-Acuity Wide-field K-band Imager (HAWK-I), a near-infrared camera on the Very Large Telescope in Chile. This telescopic hawkeye can cut right through the dust and gas that obscures the stars within the galaxy.
The image above demonstrates the difference: The picture at right shows M83 as seen in visible light by the MPG/ESO telescope, while the picture at left was produced using HAWK-I. The infrared view isn't as flashy, but it does trace the underlying structure of the galaxy's spiral arms more clearly - and pinpoints individual stars.
"This clear view is important for astronomers looking for clusters of young stars, especially those hidden in dusty regions of the galaxy," the ESO says in today's image advisory. "Studying such star clusters was one of the main scientific goals of these observations."
There are lots of other examples showing how different telescopes, operating in different wavelength, can show astronomers a "fuller spectrum." Here's just a sampling:
The data for the HAWK-I image were acquired by a team led by Mark Gieles of the University of Cambridge and Yuri Beletsky of the ESO. Mischa Schirmer of the University of Bonn performed the data processing.
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