AUGUST 28, 2010
Los Angeles Wildfires
Photograph by Steven Riley
This Month in Photo of the Day: Photos From the 2009 International Photo Contest
"From the view I had at the location, it looked as if there was a freeway leading directly to the hills of fire! It was amazing to see how life continued on despite the growing fire."—Steven Riley
See more photos, see winners' galleries, download wallpaper, and solve puzzles from the 2009 International Photo Contest.
See more photos, see winners' galleries, download wallpaper, and solve puzzles from the 2009 International Photo Contest.
A Strange Ring Galaxy
Is this one galaxy or two? Astronomer Art Hoag first asked this question when he chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark. How Hoag's Object formed remains unknown, although similar objects have been identified and collectively labeled as a form of ring galaxy. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished.
This image, taken by the Hubble Space Telescope in July 2001, reveals unprecedented details of Hoag's Object and may yield a better understanding. Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Coincidentally, visible in the gap (at about one o'clock) is yet another ring galaxy that likely lies far in the distance.
Image Credit: NASA, R. Lucas (STScI/AURA)
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