Within weeks, Reichart had confirmed the Caltech finding with even more rigorous data from a burst that took place on Feb. 28, 1997. He reported his results in a recent issue of the Astrophysical Journal . The burst's measurements were precisely consistent with a model predicting that gamma-ray bursts are produced following the collapse of a massive star, resulting in the formation of a black hole. Astronomers previously regarded quasars as the most distant objects in the universe. The most distant quasars, believed to be the seeds of young galaxies, formed at a redshift of 5.
Redshift is a measure of celestial distances.
The higher the redshift, the more distant the object. A redshift of 5 corresponds to a distance of 13 billion light years, when the universe was 7 percent of its current age. But Lamb and Reichart have calculated that gamma-ray bursts theoretically should be visible out to a redshift of 20, when the universe was only a hundred million years old, or approximately 1 percent of its current age. Beyond a redshift of 20, astronomers believe no stars were forming or collapsing to produce gamma-ray bursts. The Swift mission could see bursts out to a redshift of 70, although I doubt if such bursts exist.