Second repeating fast radio burst discovered
An international team of astronomers has discovered a second persistently active fast radio burst (FRB), posing questions about the nature of these mysterious phenomena. FRBs are intense, brief flashes of radiofrequency emissions lasting on the order of milliseconds. The phenomenon was discovered in 2007 by graduate student David Narkevic and his supervisor Duncan Lorimer. The source of these highly energetic events is a mystery, but clues as to their nature are being gradually collected.
The new source, FRB 20190520B, was detected with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Guizhou, China, on 20 May 2019 and found in data in November that year. Follow-up observations by the Jansky Very Large Array (VLA) program led by the California Institute of Technology found weaker, constant radio emissions associated with the FRB, also allowing the Subaru telescope in Hawaii to localise the source to be within the fringes of a dwarf galaxy nearly 3 billion light years from Earth. Notably, it’s the second repeating FRB to be associated with a persistent radio source (PRS), following the localisation of FRB 121102 in 2012.
“The big surprise for me was realising that the new FRB seems to be such a perfect ‘twin’ to an earlier discovery,” Casey Law, an astronomer at the California Institute of Technology, said. “Perhaps some would have preferred to say that the first such association was a coincidence, because it was hard to explain. Now the second example shows that this is a real and critical part of the life of an FRB.”