Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have discovered four examples of a new “species” of very red galaxy in the early universe. Located 13 billion light-years from Earth not even Hubble can see it. Being sensitive to infrared light NASA’s Spitzer Space Telescope has been able to reveal not one, but four very red galaxies. It’s a mystery though… what makes them so red in colour?
Astronomers can’t explain it. They might be very dusty or might contain many old, red stars, they may even be very distant. All three reasons seem to apply to the these newly discovered galaxies.
Interestingly all four galaxies are grouped near each other and appear to be physically associated. Due to their great distance, viewing from Earth shows them as they were only a billion years after the Big Bang when the first galaxies formed.
Researchers plan to search for more examples of this new “species” of very red galaxies analyzing more Spitzer and Hubble observations to track them down.