Light captured from when the Universe was still in its childhood has shown a massive galaxy that churned out nearly 3,000 stars per year, a rate 2,000 greater than our own Milky Way today, astronomers said on Wednesday.
The galaxy, called HFLS3, has a mass of stars nearly 40 billion times the mass of the Sun.
Its light, snared by a network of 12 telescopes, was emitted around 12.8 billion years ago, less than 900 million years after the birth of the cosmos, according to their study, published in Nature.
"This galaxy is proof that very intense bursts of star formation existed only 880 million years after the Big Bank," said Dominik Riechers of Cornell University in New York.
"We've gotten a valuable look at a very important epoch in the development of the first galaxies."
Separately, the European Southern Observatory (ESO) on Wednesday reported remarkable results from a brand-new telescope in the Chilean desert designed to pinpoint such "star factories" in the early Universe.
The instrument, the Atacama Large Millimetre/submillimetre Array (ALMA), uses a small forest of antennae to pick up light at relatively longer wavelengths, which penetrates dust that obscures star-forming galaxies.
ALMA was inaugurated only on March 13 but in the months before the ceremony, astronomers were able to put part of the network through its paces.
Even when incomplete, the telescope located more than 100 of the most fertile galaxies in early Universe, ESO said.
"ALMA is so powerful that, in just a few hours, it captured as many observations of these galaxies as have been made by all similar telescopes worldwide over a span of more than a decade," the observatory said in a press release.
The data is published in the Monthly Notices of Britain's Royal Astronomical Society and the Astrophysical Journal.