The CHIME telescope in Canada recently detected eight new repeating fast radio bursts. This is huge news! It brings the total number of known repeating fast radio burst sources to ten, up from the two which were previously known. (The first was discovered in 2012 and the second in 2018.)
Fast radio bursts are one of the biggest and most interesting mysteries in astrophysics today. First discovered in 2007 (the first one was discovered in archive data which was recorded in 2001), they are extremely bright, extremely brief pulses of radio waves. At the moment astronomers don’t know for sure what causes them, but one possibility is that they’re generated by magnetars (which are extremely dense objects with very strong magnetic fields).
Fast radio bursts fall into a category of event called transients. That’s a general name for anything in astronomy that changes or moves quickly, or which appears and disappears. Other types of transients include supernovae, gravitational waves, and exoplanet transits. Transients don’t always last long enough for astronomers to get a full set of observations, which can make it difficult to gather data about them, and in many cases it’s not even possible to figure out exactly where the source object is located. Often, astronomers have as little as a few minutes to track down the source and get other astronomers with different kinds of telescopes (e.g. optical or X-Ray) looking in the right direction to gather as much data as possible.
Finding repeating fast radio bursts is very useful if we want to study them and their sources. Most of the fast radio bursts seen so far were one-off events, many of which were found in archive data years after the fact. Because of that, astronomers only had a limited amount of data they could analyse about each source. That means there was very little to go on to figure out what’s causing the bursts, but finding repeating bursts might change that. Astronomers can look at FRBs from these sources over and over, gathering as much data as they like, right across the electromagnetic spectrum. They should learn a lot, and they hopefully they will be able to test their theories about what kinds of objects they’re looking at. No-one really understands fast radio bursts, so there are lots of questions waiting to be answered.
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