Optical characterization by IRAP astrophysicists of the kilonova associated with the gravitational wave event that occured on 17th August 2017

A gravitational wave event has been detected by the LIGO/Virgo gravitational wave observatories on the 17th August 2017. It quickly turned out that the signal corresponded to the fusion of two neutron stars located at about 130 million light years from Earth. A simultaneous detection in gamma rays was obtained from satellite observations. Initially the precise region in the sky was unclear and contained about fifty galaxies that may have hosted the phenomenon. In less than a day, optical telescopes were used to precisely locate the star in visible light.
At IRAP, astrophysicists used the Zadko telescope, operated with astrophysicists of the University of Western Australia, to record the visible light emitted by the star. The source was observe over several Australian nights, allowing us to observe a decrease of the light compatible with kilonova models.

This image shows, on the left, the galaxy NGC 4993 that hosted the neutron star couple. On the right, the image with the galaxy light subtracted, that shows the faint light emitted by the kilonova (where the two small white lines cross).

Further Resource

Contact IRAP

  • Alain Klotz : alain.klotz@irap.omp.eu

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