The oldest pair of compact quasars ever observed has been found only 900 million years after the Big Bang. Scientists say there is no theoretical explanation for how the pair of actively feeding black holes grew so massive at such an early time in the history of the Universe. The pair of quasars has been given the Hawaiian nickname Nāpōwawāʻenakaulua.
An international team of astronomers has discovered J1602+4228AB, nicknamed Nāpōwawāʻenakaulua, the most distant, and thus oldest, compact pair of quasars ever found in the Universe. Their close separation also makes them the most compact pair of quasars found in the early-Universe era known as cosmic dawn. While astronomers theorize that quasar pairs are common, actually finding and characterizing these energetic objects is rare. Even rarer — finding them this early in the history of the Universe.
Nāpōwawāʻenakaulua’s surprising nature was revealed through observations with the Gemini North telescope, located on the dormant volcano Maunakea in Hawai‘i, and the James Webb Space Telescope ( JWST ). Silvia Onorato, a postdoctoral research associate at NSF NOIRLab, led the study. The results are presented in a paper published in The Astrophysical Journal Letters .
Gemini North is one half of the International Gemini Observatory, an international collaboration led by the U.S. National Science Foundation, in partnership with Canada, Chile, Brazil, Argentina, and the Republic of Korea, and operated by NSF NOIRLab.
The first billion years of cosmic time were a period of furious assembly: dark matter halos collapsed, galaxies ignited their first generation of stars, and massive galaxies formed the very first supermassive black holes at their centers. As galaxies interacted, collided, and in some cases merged completely, their supermassive black holes were fed with large quantities of gas and stars. A fraction of this “accreted mass” from feeding was converted into energy, causing the black holes to become so bright as to outshine all the stars in their host galaxy. These are what astronomers call quasars .
Scientists have established that galaxy interactions and mergers are common in the Universe. Therefore, they expect to find an abundance of pairs of quasars with a separation less than the typical size of a galaxy. However, this has proven difficult for a few reasons: 1) a supermassive black hole’s “quasar phase” is relatively short; 2) these objects are very far away, so they are faint and hard to detect with ground-based telescopes; 3) at such small separation scales, the individual members of a quasar pair are hard to resolve.
Enter Nāpōwawāʻenakaulua, which is not only the third known quasar pair found at cosmic dawn, but it was found so early in the history of the Universe that scientists cannot explain how it came into existence. The nature of Nāpōwawāʻenakaulua is captured in its name, which translates to “Two celestial bodies of fathomless powerful darkness in the brilliance of heat reincarnating energy into the Universe,” as created by the A Hua He Inoa program at the ʻImiloa Astronomy Center of Hawaiʻi and the University of Hawai‘i’s Ka Haka ʻUla O Keʻelikōlani (Hawaiian Language College) [1] .
The pair is separated by a distance of approximately 18,100 light-years, or roughly one-fifth the diameter of the Milky Way Galaxy. They have masses of 1.5 billion and 400 million times that of the Sun, respectively. Their distance from us places them at only 900 million years after the Big Bang. During this period, the Universe’s first stars, galaxies, and black holes were still relatively young. The extreme mass of Nāpōwawāʻenakaulua at this time therefore challenges our current understanding of how large-scale cosmic structures are formed.
“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,” says Onorato. “ We observed Nāpōwawāʻenakaulua at a time when the Universe was only a thirteenth of its age and astonishingly, its supermassive black holes are just as massive as those we see today.”
Nāpōwawāʻenakaulua was uncovered in data from the Aether survey , a JWST program led by Emanuele Paolo Farina, Associate Scientist at NSF NOIRLab/Gemini, aimed at compiling a census of objects in the early Universe. Using JWST’s Near-Infrared Spectrograph Integral Field Unit, the survey collected a sample of 200 quasars, representing 43% of all known quasars at this stage of cosmic history. It was during visual inspections of the Aether dataset that the team made the exciting discovery that quasar J1602+4228A had a companion.
Follow-up observations with Gemini North’s Gemini Near-Infrared Spectrograph ( GNIRS ) allowed the team to resolve the two quasars as individuals. J1602+4228A and B are so close together, and J1602+4228B is so faint, that observing it from the ground should have been nearly impossible. However, perfect timing and perfect weather conditions on Maunakea allowed the team to accomplish this scientific feat. “The sky over Maunakea was so clean and sharp that we managed to collect the data in only two nights,” says Onorato. Additional observations with the Gemini Multi-Object Spectrograph ( GMOS ) further constrained the properties of the quasar pair [2] .
While the complete origin story of Nāpōwawāʻenakaulua remains a mystery, the team proposes that this rare quasar pair may serve as a signpost of an extreme peak in the matter density field of the early Universe, where galactic interactions simultaneously fed star formation and the rapid growth of the black holes.
“Nāpōwawāʻenakaulua is a really unique environment,” says Onorato. “It’s a laboratory for astronomers to study how the very first massive galaxies and their central black holes assembled together through direct galaxy interactions during these early times.”
[1] The A Hua He Inoa (AHHI) program utilizes traditional naming practices, and often works with students, teachers, and community members who are fluent in ‘Ōlelo Hawaiʻi, the indigenous language of Hawaiʻi. Nāpōwawāʻenakaulua was created by Larry Kimura, a professor at Ka Haka ʻUla O Keʻelikōlani. It combines Nā (plural indicator), Pō (fathomless powerful darkness) to represent the supermassive black holes, Wawā (reincarnation or procreation as referenced from hānau wawā in Pukui-Elbert (1986) dictionary), ʻEna (brilliance of heat) to represent the bright radiation emitted from the matter accreting onto the central black holes, and Kaulua (double or pair) to represent the two quasars. Nāpōwawāʻenakaulua also harkens back to two previously named objects from AHHI: Pōwehi , the first image of a black hole in 2019, and Pōniuāʻena , the furthest quasar discovered at the time in 2020.
[2] GMOS was used to investigate whether a gravitational lens positioned in front of the quasar pair was creating the appearance of the second, fainter quasar. Differences in the shape of each quasar's spectra led the team to favor that this is a real physical pair; however, a lens model is needed to definitively rule out gravitational lensing.
This research is presented in a paper titled “ Nāpōwawā‘enakaulua : a close quasar pair at cosmic dawn in the Aether survey” appearing in The Astrophysical Journal Letters . DOI: 10.3847/2041-8213/aeb11f
The team is composed of S. Onorato (NSF NOIRLab/International Gemini Observatory [Gemini], USA), E. P. Farina (NSF NOIRLab/Gemini, USA/Italian National Institute for Astrophysics [INAF], ITA), R. Decarli (INAF, ITA), K. Protušová (Heidelberg University, DEU), E. Pizzati (Center for Astrophysics | Harvard & Smithsonian, USA), D. Pelliccia (UC Santa Cruz, USA), D. S. Chu (University of Hawai‘i, USA), L. L. Kimura (Ka Haka ‘Ula O Ke‘elikōlani/College of Hawaiian Language, USA), L. Lozi (NSF NOIRLab/Gemini, USA), E. Peavy (NSF NOIRLab/Gemini, USA), F. Arrigoni–Battaia (Max Planck Institute for Astrophysics [MPA], DEU), E. Bañados (Max Planck Institute for Astronomy [MPIA], DEU), A. J. Barth (University of California, Irvine, USA), S. Belladitta (MPA, DEU/INAF, ITA), M. Bischetti (University of Pisa/INAF, ITA), S. E. I. Bosman (Heidelberg University/MPIA, DEU), H. Choi (University of Michigan [U-M], USA), T. Costa (Newcastle University, GBR), A. Eilers (Massachusetts Institute of Technology, USA), X. Fan (University of Arizona [UA], USA), S. Gallerani (Scuola Normale Superiore, ITA), T. R. Geballe (NSF NOIRLab/Gemini, USA), A. J. Gloudemans (NSF NOIRLab/Gemini, USA), E. Kim (NSF NOIRLab/Gemini, USA), B. C. Lemaux (NSF NOIRLab/Gemini, USA), W. Liu (UA, USA), Y. Matsuoka (Ehime University, JPN), C. Mazzucchelli (Universidad Diego Portales, CHL), A. Nitta (NSF NOIRLab/Gemini, USA), J. Schindler (University of Hamburg, DEU), A. W. Stephens (NSF NOIRLab/Gemini, USA), H. Suh (NSF NOIRLab/Gemini, USA), F. Walter (MPIA, DEU), F. Wang (U-M, USA), and J. Yang (U-M, USA).
NSF NOIRLab , the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF , NRC–Canada , ANID–Chile , MCTIC–Brazil , MINCyT–Argentina , and KASI–Republic of Korea ), NSF Kitt Peak National Observatory ( KPNO ), NSF Cerro Tololo Inter-American Observatory ( CTIO ), the Community Science and Data Center ( CSDC ), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE ’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy ( AURA ) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona.
The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.
The Astrophysical Journal Letters
Nāpōwawā‘enakaulua: a close quasar pair at cosmic dawn in the Aether survey
10-Nov-2026