|17th of August 2018|
|GW170817, one year on|
|by Dougal Dobie|
One year ago today, on August 17, 2017, the Advanced LIGO and Virgo
detectors observed the first detected neutron star merger,
GW170817. Seconds later a burst of gamma-rays was detected by the
Fermi Gamma-ray Burst Monitor, and within the following few hours a
counterpart was detected with optical, infrared and ultraviolet
telescopes. The CSIRO's Australia Telescope Compact Array (ATCA) was
the first radio telescope to begin follow-up of the event, starting
observations 13 hours post-merger.
The Very Large Array (VLA) made the first detection of a radio counterpart 16 days post-merger, which was rapidly confirmed by an observation with the ATCA. The three images above are taken from an animation consisting of a series of 12 images taken with the ATCA showing how the source (white crosshairs) has evolved over the past year. Changes in the shape of the source are due to different array configurations and hour angle coverage. Credit: Dougal Dobie, Emil Lenc, Mark Wieringa, Tara Murphy, David Kaplan.