Wheel or Weapon? Telescope Reveals Galaxy’s Ring of Fire

Image: NGC 1291
A new image from NASA's Spitzer Space Telescope, taken in infrared light, shows where the action is taking place in the barred spiral galaxy NGC 1291. The outer ring, colored red in this view, is filled with new stars that are igniting and heating up dust that glows with infrared light. The stars in the central area produce shorter-wavelength infrared light than that seen in the ring, and are colored blue. NASA / JPL-Caltech

An ancient galaxy blazes with a fresh surge of starbirth in a newly released infrared image from NASA's Spitzer Space Telescope — a fiery view that has sparked comparisons to the weapon wielded by Xena the Warrior Princess on TV.

The barred spiral galaxy, known as NGC 1291, lies about 33 million light-years away in the constellation Eridanus. It's thought to have come into existence relatively early in the history of the universe, perhaps as far back as 12 billion years ago. The galaxy's S-shaped central bar of stars, which shows up here mostly in shades of blue, represents the old neighborhood — where much of the gas available for star formation has been used up.

Spitzer's view highlights an outer ring of fire where astronomers say gas is being trapped and ignited in a star-forming frenzy. "The rest of the galaxy is done maturing," Kartik Sheth of the National Radio Astronomy Observatory said Wednesday in a Spitzer news release. "But the outer ring is just now starting to light up with stars."

Sheth and his colleagues are studying NGC 1291 and more than 3,000 other galaxies in our celestial neighborhood as part of a program called the Spitzer Survey of Stellar Structure in Galaxies, or S4G.

The structure of NGC 1291 might remind Sheth and other astronomers of a wheel with spokes — but for fans of the "Xena" show, it looks more like the S-barred, ring-shaped chakram that the warrior princess threw with abandon. A wheel or a weapon? You decide.