Astrophys. J. 709, 210–217 (2010)

Astronomers have discovered the glow of a dusty galaxy about 7.3 billion parsecs away that existed when the Universe was just 1.5 billion years old. Kirsten Knudsen of the Argelander Institute for Astronomy in Bonn, Germany, and her colleagues say that it is the earliest-known faint galaxy of its type — a type thought to incubate violent episodes of star birth.

An array of antennas in Hawaii detected the galaxy's diffuse, glowing dust in the microwave part of the spectrum. Follow-up observations with optical telescopes determined its age. The discovery suggests that small and faint dusty galaxies might be as important for star formation in the early Universe as their bigger and brighter counterparts.