NOIRLab reports the oldest known compact quasar pair, seen 900 million years after the Big Bang

An international team using the Gemini North telescope on Maunakea in Hawaiʻi and the James Webb Space Telescope has found what NSF NOIRLab calls the most distant, and therefore oldest, compact pair of quasars yet known. The two objects, cataloged as J1602+4228A and B and nicknamed Nāpōwawāʻenakaulua, are seen as they were about 900 million years after the Big Bang. The results were published on November 10, 2026, in The Astrophysical Journal Letters, and NOIRLab, which operates Gemini, announced them the same day.

NASA describes a quasar as an enormously bright, compact source in the distant universe, thought to be a supermassive black hole drawing in matter, that typically gives off thousands of times more light than a galaxy like ours; more than a million have been cataloged. Because galaxies often interact and merge, astronomers expect close pairs of quasars to be common, but NOIRLab says they are hard to find: the quasar phase is short, distant pairs are faint, and close companions are difficult to tell apart.

What the team measured

The paper's authors, led by Silvia Onorato, a postdoctoral research associate at NOIRLab, measure a projected separation of 0.98 arcseconds, or about 5.56 kiloparsecs at the pair's redshift of roughly 6.08. NOIRLab puts that at about 18,100 light-years, around a fifth of the Milky Way's diameter. The two black holes weigh about 1.5 billion and 400 million times the mass of the Sun, and the quasars' velocities differ by only about 15 kilometers per second, according to the paper.

How it turned up

The pair surfaced in the Aether survey, a Webb program led by Emanuele Paolo Farina of NOIRLab and Gemini that has gathered spectra of 200 quasars with the telescope's NIRSpec integral field unit. NOIRLab says that is 43% of all quasars known from that stage of cosmic history. While inspecting the data by eye, the team noticed that the quasar J1602+4228A had a companion. Follow-up with the GNIRS spectrograph on Gemini North then separated the two from the ground. Onorato said very sharp skies over Maunakea let the team collect the data in two nights, and the GMOS instrument added further constraints.

Why it is a puzzle

“There is no definitive theoretical explanation for how a single one of these giant quasars exists so early in the age of our Universe, much less two,” Onorato said in the NOIRLab release. In the paper, the team compares the chance of finding such a close pair with extrapolations of how early quasars cluster on larger scales and reports an excess of two to three orders of magnitude, a factor of roughly 100 to 1,000 by our conversion. The authors say this hints at a population of quasar pairs set off by galaxy mergers at cosmic dawn, or at an environment denser than average. NOIRLab notes that it is only the third quasar pair known from cosmic dawn, and says the team proposes it may mark an extreme peak in the density of matter in the early universe.

Not yet certain

The paper's abstract is more cautious than the release. It does not call the pair the oldest known, and where the release calls it the most compact pair found at cosmic dawn, the abstract calls Nāpōwawāʻenakaulua “the most compact known quasar pair candidate in the Epoch of Reionization.” The team used GMOS to test whether a gravitational lens in front of the system could be making a second, fainter quasar appear. According to NOIRLab, differences in the shapes of the two quasars' spectra led the researchers to favor a real physical pair, but a lens model is needed to rule out lensing definitively.

The name

The Hawaiian name was created by Larry Kimura, a professor at Ka Haka ʻUla O Keʻelikōlani, the University of Hawaiʻi's Hawaiian language college, through the A Hua He Inoa naming program at the ʻImiloa Astronomy Center of Hawaiʻi and the college. NOIRLab says it combines elements for a plural, fathomless powerful darkness, reincarnation, the brilliance of heat and a pair. It also recalls two earlier names from the program: Pōwehi, given to the first image of a black hole in 2019, and Pōniuāʻena, the most distant quasar known when it was found in 2020.