Astronomers Spot One of the Oldest Galaxies in the Universe

From its perch on the summit of a 15,000-foot tall dormant volcano in Puebla, Mexico, the Large Millimeter Telescope can peer into the corners of the universe. Now, a team of astronomers from the University of Massachusetts Amherst and Mexico’s National Institute of Astrophysics, Optics, and Electronics have capitalized on the LMT’s high resolution and sensitivity, discovering a 12.8 billion-year-old galaxy—one of the oldest objects yet found in the universe.

The dusty, star-forming galaxy took shape in the first billion years after the Big Bang and is likely to be one of the first galaxies to ever form, says Min Yun, astrophysicist of the University of Massachusetts Amherst, in a press release.

"Seeing an object within the first billion years is remarkable because the universe was fully ionized, that is, it was too hot and too uniform to form anything for the first 400 million years,” Yun says in the release, “so our best guess is that the first stars and galaxies and black holes all formed within the first half a billion to one billion years."

The galaxy, dubbed G09 83808, was originally detected by NASA’s Herschel Space Telescope, Futurism’s Claudia Geib reports. The instrument, however, could only capture blurry images, so NASA passed the project on to the LMT team.

The researchers, who described the find in a recent paper published in the journal Nature Astronomy, determined the galaxy’s distance using what's known as its redshift. When a light source is moving away from the observer, the wavelengths of light stretch out and veer toward the red end of the spectrum. When studying galaxies, redshifts occurs due to the constant expansion of the universe. So the greater the redshift, the greater the distance.

“These high redshift, very distant objects are a class of mythical beasts in astrophysics,” Yun says. “We always knew there were some out there that are enormously large and bright, but they are invisible in visible light spectrum because they are so obscured by the thick dust clouds that surround their young stars.”

G09 83808 is not the oldest galaxy. In 2012, the Hubble space telescope spotted a galaxy that formed around 500 million years after the Big Bang. In 2016, Hubble captured an image of the galaxy GN-z11, which is located 13.4 billion light-years away. This means it came into existence just 400 million years after the Big Bang.

And there are likely more discoveries to come. The LMT won’t be fully operational until this winter, but it promises to be the largest, most sensitive single-aperture tool of its kind. Armed with a telescope capable of detecting extremely faint, distant objects like G09 83808, Yun and the rest of his team are optimistic that they'll make similar discoveries in the future.

“Every time I reduce one of these data sets I'm full of anticipation,” Yun says. “I'm always hoping that these [objects] will pop out. You have to be a hopeless optimist to be doing this kind of work, and this time it absolutely paid off." 

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's associate digital editor, history.