\n<\/p>\n
\n Step back 1000 years, look up at the night sky and you might notice some extra dots of light compared with today. Back then, Chinese astronomers called these \u201cguest stars\u201d and believed them to be harbingers of great change.<\/p>\n We now know these were likely\u00a0to have been\u00a0supernovae \u2013 explosions borne from dying stars \u2013 and they\u00a0are one of many\u00a0happy accidents caught\u00a0when astronomers\u00a0were looking\u00a0at\u00a0the right\u00a0spot\u00a0at the right time.<\/p>\n But at the turn of this century, looking for these \u201ctransient\u201d events became a tactic in its own right, and it is changing the way we do astronomy altogether. We have since found a myriad of intermittent events throughout the cosmos, lasting from nanoseconds to longer than a human lifetime.<\/p>\n \u201cYou think the universe has a different range of spatial scales, but it also has these ranges of time scales, and they\u2019re incredibly poorly explored in astronomy,\u201d says Jason Hessels\u00a0at the University of Amsterdam in the Netherlands.<\/p>\n Relying on chance to capture these events risks missing much of the action, so astronomers have now automated the process of serendipity, with surveys like the Palomar Transient Factory, which ran from 2009 to 2012, coordinating telescopes as one well-oiled machine. The main telescope in San Diego, California, would see an interesting flash and another would investigate further. \u201cIt was really set up like a conveyor belt,\u201d says Hessels.<\/p>\n Many more telescopes whose purpose is to search in time, rather than space, have followed. These include the Zwicky Transient Facility, Palomar\u2019s successor, and the Pan-STARRS survey, which has collected the largest volume of astronomical data of all time, at 1.6 petabytes, from its perch in Hawaii.<\/p>\n <\/p>\n These telescopes and others have produced a torrent of data that has unveiled the universe\u2019s blinks and flashes: gamma-ray bursts, fast radio bursts, gravitational waves and stars exploding either of their own accord or because they are being torn apart by black holes.<\/p>\n Transient astronomy is transforming the way we depict the universe. \u201cWe started with drawings, and then we had photographs, and then we had something like stop-motion film,\u201d says Hessels. Now, we are getting closer to a full movie, he says. \u201cIt seems like every time we tweak the way we look at the sky, we fill in more and more of the movie.\u201d<\/p>\n Topics:<\/p>\n<\/section><\/div>\n