IOK-1 is a distant galaxy in Coma Berenices

Coma Berenices

Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole...

. When discovered in 2006, it was the oldest and most distant galaxy

Galaxy

A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

 ever found, at redshift 6.96.

It was discovered in April 2006 by Masanori Iye at National Astronomical Observatory of Japan

National Astronomical Observatory of Japan

The is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations - the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude...

 using the Subaru Telescope in Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 and seen as it was 12.88 billion years ago. Its emission of Lyman alpha radiation has a redshift

Redshift

In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum...

 of 6.96, corresponding to just 750 million years after the Big Bang

Big Bang

The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...

. While some scientists have claimed other objects (such as Abell 1835 IR1916

Galaxy Abell 1835 IR1916

Abell 1835 IR1916 was a candidate for being the most distant galaxy ever observed. It was claimed to lie behind the galaxy cluster Abell 1835, in the Virgo constellation...

) to be even older, the IOK-1's age and composition have been more reliably established.

"IOK" stands for the observers' names Iye, Ota, and Kashikawa.