I led a team that discovered the most-distant known object in the universe — a gamma-rayburst. Our observations showed that this exploding star,dubbed GRB 090423, took place when the cosmos wasonly 625 million years old, a mere 4.6% of its current age.The discovery of this extraordinary event pushes our viewof the universe earlier by 155 million years, bringing usever closer to the first generation of stars and galaxies.We could detect this gamma-ray burst (GRB) at suchan extreme distance because these explosions are themost luminous objects in the universe other than the BigBang itself. Unfortunately, the bursts fade away quickly.The gamma-ray emission lasts from a few milliseconds toseveral minutes, while the afterglows — the X-ray, visible,and infrared dying embers — disappear in hours to days.
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