Iris Nebula

The Iris Nebula, designated NGC 2703 by human astronomers, is a reflection nebula approximately 1,300 lightyears away from Earth in the Cepheus constellation. Within the nebula, dusty nebular material (ie; interstellar dust and gas) surrounds a massive, hot, young star in its formative years. Central filaments of cosmic dust glow with a reddish photoluminescence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. The nebula's dominant color, blue, is the result of dust grains reflecting star light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. As shown here, the Iris Nebula is about 6 light-years across.

During the Iris ARG, it was speculated that the Iris Nebula was the location of the Ark. However, because the Ark is located approximately 218 lightyears away from the galactic centre of the Milky Way, well outside the galaxy, it seems that the nebula must be the location of another important Forerunner artefact.

After the events of Halo 3, the Master Chief and Cortana were left stranded in space near a Forerunner artefact, and it has been speculated, due to the nebula in the background, that they are in or near the Iris Nebula.