The Farthest Thing Ever Seen

A faint gamma-ray burst (GRB) captured by NASA’s Swift satellite has smashed the record for the earliest, most-distant known object in the universe — with a redshift of about 8.2.

The burst, named GRB 090423 for its discovery date, went off in Leo and was seen to last for 10 seconds. Several teams, including a group using the Gemini-North telescope in Hawaii and a European group using the Very Large Telescope in Chile, followed up the Swift detection by observing the burst’s fading infrared afterglow. Based on how much the afterglow’s light was redshifted (stretched) by cosmic expansion since the era when the burst happened, the group determined that it went off about 630 million years after the Big Bang.

This means that the GRB's gamma rays traveled for a mind-boggling 13.1 billion years before reaching Earth. That's so far back in time that it's meaningless to assign a specific "distance," since large distances in the universe have themselves expanded by a factor of 9.2 since that time. From the burst's perspective, Earth's formation lay 8.5 billion years in the future.

Source: Gemini Observatory / NSF / AURA / D. Fox / A. Cucchiara / E. Berger

See the press releases put out by NASA, the European Southern Observatory, the U.K.'s Science and Technology Facilities Council, and the Gemini Observatory.