Giant rings of ultraviolet light have been spotted around some ancient galaxies, sending some scientists reeling from the completely unexpected phenomenon.
The odd ultraviolet formations were spotted around several aged galaxies that astronomers had presumed to be astronomically dead – inactive, that is.
"We haven't seen anything quite like these rings before," said researcher Michael Rich at the University of California, Los Angeles, in a statement. "These beautiful and very unusual objects might be telling us something very important about the evolution of galaxies."
Astronomers observed the ultraviolet rings using two orbiting space observatories: NASA's Galaxy Evolution Explorer and Hubble Space Telescope. They studied 30 elliptical and lens-shaped "early" galaxies with strong UV emissions to determine why they – though ancient and having no visible signs of star formation – were still emitting such energetic light.
NASA announced the discovery this month. Details of the research appeared in the April 21 issue of the Astrophysical Journal.
Mystery rings in deep space
While young and lively galaxies have bluish hues from their active stars, older galaxies emit reddish collective starlight, NASA officials said in a statement. This reddish trait of the stars in the ancient galaxies allowed scientists to peg the ages of most of the stars at around 10 billion years old.
When astronomers studied the same galaxies with the Hubble Space Telescope, scientists discovered the source of the energetic look.
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