Energetic explosion’s remnant detected by California telescope
Courtesy of Brad Cenko
BALTIMORE — An incredibly energetic explosion in the cosmos has been discovered via its not-so-energetic afterglow. Each year, astronomers observe several hundred of these explosions, known as gamma-ray bursts, but this marks the first time they spotted a burst’s remnant radiance before detecting the burst itself. The finding, reported April 12 at a meeting of the American Physical Society, could enable the detection of other bursts whose high-energy signatures elude space telescopes.
A small fraction of gargantuan stars end their lives in spectacular explosions that send a narrow beam of gamma rays, the universe’s highest energy radiation, darting through space. Specialized space telescopes typically identify these bursts by detecting sudden flashes of gamma rays. But in February 2014, a 1.2-meter telescope in southern California spotted a visible-light flash that brightened dramatically within