“Naked-Eye” Gamma-Ray Burst Was Aimed Squarely At Earth
‘Data from satellites and observatories around the globe show a jet from a powerful stellar explosion witnessed March 19 was aimed almost directly at Earth.
NASA’s Swift satellite detected the explosion – formally named GRB 080319B – at 2:13 a.m. EDT that morning and pinpointed its position in the constellation Bootes. The event, called a gamma-ray burst, became bright enough for human eyes to see. Observations of the event are giving astronomers the most detailed portrait of a burst ever recorded.
“Swift was designed to find unusual bursts,” said Swift principal investigator Neil Gehrels at NASA’s Goddard Space Flight Center in Greenbelt, Md. “We really hit the jackpot with this one.”
In a paper to appear in Thursday’s issue of Nature, Judith Racusin of Penn State University and a team of 92 coauthors report on observations across the spectrum that began 30 minutes before the explosion and followed its afterglow for months. The team concludes the burst’s extraordinary brightness arose from a jet that shot material directly toward Earth at 99.99995 percent the speed of light.’