Astronomers using NASA’s Spitzer and Hubble space telescopes have discovered that one of the most distant galaxies known is churning out stars at a shockingly high rate. The blob-shaped galaxy, called GN-108036, is the brightest galaxy found to date at such great distances.
The galaxy, which was discovered and confirmed using ground-based telescopes, is 12.9 billion light-years away. Data from Spitzer and Hubble were used to measure the galaxy’s high star production rate, equivalent to about 100 Suns per year. For reference, our Milky Way Galaxy is about five times larger and 100 times more massive than GN-108036, but makes roughly 30 times fewer stars per year.
“The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe,” said Mark Dickinson from the National Optical Astronomy Observatory in Tucson, Arizona. “Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation.”
The international team of astronomers, led by Masami Ouchi from the University of Tokyo, Japan, first identified the remote galaxy after scanning a large patch of sky with the Subaru Telescope atop Mauna Kea in Hawaii. Its great distance was then carefully confirmed with the W.M. Keck Observatory, also on Mauna Kea.
“We checked our results on three different occasions over two years, and each time confirmed the previous measurement,” said Yoshiaki Ono from the University of Tokyo.
GN-108036 lies near the beginning of time itself, a mere 750 million years after our universe was created 13.7 billion years ago in the “Big Bang.” Its light has taken 12.9 billion years to reach us, so we are seeing it as it existed in the distant past.
Astronomers refer to the object’s distance by a number called its “redshift,” which relates to how much of its light has stretched to longer, redder wavelengths due to the expansion of the universe.