NASA's Swift Turned Fast Enough to Catch a 0.03-Second Gamma-Ray Burst
NASA's Neil Gehrels Swift Observatory has ended its science mission. It is orbiting less than 171 miles above Earth, where greater atmospheric drag prevents its telescopes from steadily gazing at their targets.
Short gamma-ray bursts reach peak brightness in less than two seconds. Until Swift, it had been impossible to locate these bursts rapidly and precisely enough to observe their afterglows. In May 2005, Swift achieved that with GRB 050509B, which lasted just 0.03 seconds. Swift turned to the burst fast enough to detect 11 X-ray photons, making this the first short burst with a detected afterglow.
AI-generated discussion · Different perspectives
Eleven X-ray photons sounds like a rounding error, but they came from a 0.03-second burst and were enough to make it the first short gamma-ray burst with a detected afterglow.
The harder problem was not collecting photons but finding the burst fast enough; short bursts peak in under two seconds, and before Swift it was impossible to locate them precisely enough to observe afterglows.