GN-z11

The object's name is derived from its location in the GOODS-North field of galaxies and its high cosmological redshift number (GN + z11). It is observed as it existed 13.4 billion years ago, just 400 million years after the Big Bang; as a result, its distance is sometimes inappropriately reported without qualification as 13.4 billion light-years, its light-travel distance measurement.

In early 2023, the James Webb Space Telescope observed the galaxy and reported a definitive redshift of z = 10.6034 ± 0.0013.

The galaxy has such a high redshift that its angular diameter distance is actually less than that of some galaxies with lower redshift. This means that the ratio of its angular size (how big it appears in the sky) to its size in light-years is greater.

Discovery

The galaxy was identified by a team studying data from the Hubble Space Telescope's Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and Spitzer Space Telescope's Great Observatories Origins Deep Survey-North (GOODS-North). The research team used Hubble's Wide Field Camera 3 to measure the distance to GN-z11 spectroscopically, measuring the redshift caused by the expansion of the universe. The findings, which were announced in March 2016, revealed the galaxy to be farther away than originally thought, at the distance limit of what the Hubble Telescope can observe. GN-z11 is around 150 million years older than the previous record-holder EGSY8p7, and is observed (shortly after but) "very close to the end of the so-called Dark Ages of the universe", and (during but) "near the very beginning" of the reionization era.

Compared with the Milky Way galaxy, GN-z11 is 1⁄25 of the size, has 1% of the mass, and is forming new stars approximately twenty times as fast. With a stellar age estimated at 40 million years, it appears the galaxy formed its stars relatively rapidly. The fact that a galaxy so massive existed so soon after the first stars started to form is a challenge to some current theoretical models of the formation of galaxies.

In 2026, From an ArXiv Pre-Print astronomers using the JWST confirmed the presence of a strong He II emission from a region designated as Hebe, located approximately 3 kiloparsecs from GN-z11. The He II emission is spectrally resolved into two distinct components (C1 and C2), where C1 region is thought to potential contain Population III stars and C2 region to contain Population II stars. Population III stars scenario is taken into consideration due to absence of metal emission lines while other scenarios have also been taken into consideration like metal-poor Wolf-Rayet stars and Direct collapse black hole or Primordial black hole, but Population III star scenario is thought to be the most likely.