Euclid Telescope Spots 31 Ancient Quasars, Including Two Record-Breakers

The European Space Agency's Euclid space telescope has discovered 31 exceptionally ancient quasars, including two that set a new record as the earliest ever observed, the agency said.

The two record-breakers were already radiating as much light as a trillion Suns when the universe was only about 670 million years old, roughly 5% of its present age, according to ESA. Their light has taken some 13 billion light-years to reach Earth.

Quasars are among the brightest objects in the cosmos. They appear during a relatively short period in a galaxy's history when huge quantities of gas and other material spiral toward its central supermassive black hole. The process releases extraordinary amounts of energy, causing the galaxy's core to shine hundreds or even thousands of times more brightly than the rest of the galaxy combined.

A hidden population comes into view

Until now, astronomers had identified only a small fraction of the quasars that existed in the universe's earliest period. Most known examples were exceptionally luminous objects that stood out because they were easier to detect, leaving scientists with a skewed picture of the broader population.

Euclid is changing that. The telescope's ability to survey enormous regions of the sky and detect faint objects produced the unprecedented collection of 31 early quasars. According to NASA, which contributes to the mission, 12 of the objects date to the first 770 million years of the universe.

"These early quasars date back to the Universe's infancy," said Daming Yang of Leiden University in the Netherlands, lead author of the Euclid discovery paper. "By finding and studying them, we can better understand how these enormous systems formed and grew so quickly - one of the greatest mysteries in astrophysics."

"Euclid is a true game-changer," Yang added. "Before, we could only find a handful of the very brightest ancient quasars, but Euclid lets us search far more efficiently across huge areas of sky."

Probing dark energy and the early cosmos

Finding quasars from the universe's earliest years is extremely difficult. Few galaxies had grown large enough to host such objects at that early stage, and the faint light reaching us today can be hard to distinguish from stars much closer to Earth.

Launched in 2023, Euclid is imaging billions of galaxies to improve understanding of dark energy, the phenomenon driving the accelerating expansion of the universe. ESA said the findings will help inform plans for NASA's forthcoming Nancy Grace Roman Space Telescope, which will offer further insights into that mystery.

A new study detailing the results was published in the journal Astronomy & Astrophysics.