Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2006 February 6
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

The N44 Superbubble
Credit & Copyright: Gemini Obs., AURA, NSF

Explanation: What created this gigantic hole? The vast emission nebula N44 in our neighbouring galaxy the Large Magellanic Cloud has a large, 250 light-year hole and astronomers are trying to figure out why. One possibility is particle winds expelled by massive stars in the bubble's interior that are pushing out the glowing gas. This answer has been recently found to be inconsistent with measured wind velocities, however. Another possibility is that the expanding shells of old supernovae have sculpted the unusual space cavern. An unexpected clue of hot X-ray emitting gas was recently been detected escaping the N44 superbubble. The above image, here digitally sharpened, was taken in three very specific colours by the huge 8-metre Gemini South Telescope on Cerro Pachon in Chile.

Tomorrow's picture: larger than pluto


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