In 2007 Duncan Lorimer and colleagues scoured archival data from a 2000–01 survey of the Magellanic Clouds and discovered an energetic radio pulse of less than 5 ms duration. Since that discovery, about 20 more so-called fast radio bursts (FRBs) have been reported. One of them, identified in 2014, has now been shown to have a property that sets it apart from all its brethren: It bursts repeatedly. Laura Spitler of the Max Planck Institute for Radio Astronomy and company spotted the source, named FRB121102 (because its first burst was on 2 November 2012), in data taken with the Arecibo Observatory’s William E. Gordon Telescope, pictured here. In May and June 2015, the Gordon telescope pointed to the location of FRB121102 for follow-up observations. Spitler and colleagues discovered 10 additional bursts, whose separations ranged from 23 s to 572 s.
Astronomers are puzzling over the nature of FRB emitters....
