Euclid Has Discovered 31 Ancient Quasars. Two of Them Are Now the Oldest Ever Seen.

Euclid has caught 31 quasars that rank among the most ancient luminous objects ever catalogued — and two of them are now the oldest quasars anyone has ever observed, blazing away when the universe was only 670 million years old, or roughly 5% of its current age. That translates to light that has been travelling for about 13 billion years to reach the telescope’s detectors.

The discovery was led by ESA with NASA contributions and published on July 6, 2026 in Astronomy & Astrophysics by Daming Yang et al. It more than doubles the known number of quasars at redshift 7 or above in a single sweep. Of the 31, 12 date to the first 770 million years of the universe’s history — of which the two record-holders are a subset.

Those two record-holders have designations to match their obscurity: EUCL J172902.75+641018.1 at redshift 7.77 and EUCL J125308.55+705432.3 at redshift 7.69. Redshift is how astronomers gauge distance (and therefore age) for objects this far away — the higher the number, the older and more distant the object. Both are comfortably above the redshift-7 threshold that previously marked the edge of the reliable quasar survey sample.

A quasar is the intensely bright nucleus of a galaxy powered by a supermassive black hole actively feeding on surrounding material. Finding them at these redshifts means catching them in the process of igniting during a period cosmologists call cosmic dawn, when the first luminous structures were starting to heat and reionize intergalactic hydrogen that had gone neutral after the Big Bang. A coherently measured handful of sources at these distances has been the missing data set for modelling how quickly those structures appeared and grew.

The previous inventory of quasars at redshift 7 and above was small enough that each new find mattered. Thirty-one new sources — twelve from the earliest 770 million years alone — is the kind of jump where the error bars around population models start to narrow rather than merely wobble. It’s the first sample large enough to say something structured about how many luminous quasars were active at this epoch and how rapidly they accumulated mass in order to be burning so bright so early.

Euclid is achieving this without the kind of targeted follow-up campaigns that quasar surveys have traditionally required. The telescope was designed and built at ESA, with hardware and instrument contributions from NASA, and launched in July 2023 with a primary mission to map the geometry of the dark universe using cosmic shear and galaxy clustering. Finding early quasars is a secondary payoff, powered by the same wide-field survey data Euclid is steadily collecting across the sky — which is why the quantity of new discoveries arrived faster than most forecasts predicted.

For anyone tracking the pace of this particular frontier: the jump from a handful of known quasars at redshift 7-plus to a population of thirty-two (the original known sources plus thirty-one new ones) is the kind of data-window opening that existing models of early universe black hole growth haven’t had to contend with until now. The numbers themselves — 13 billion light-years, 670 million years, redshift 7.77 — are getting more precise and more populated, and the next round of Euclid catalogues should do the same thing again.

Sources

• Euclid discovers the most ancient quasar in the Universe — European Space Agency (ESA)
• ESA’s Euclid Space Telescope Finds Universe’s Most Ancient Quasars — NASA Science