These
records have raised hopes that, for the first time, scientists may have glimpsed
electromagnetic radiation — light — produced in tandem with gravitational waves.
The CALLISTO (Compound Astronomical Low - cost Low - frequency Instrument for Spectroscopy in Transportable Observatory) spectrometers, designed and built by electronics engineer Christian Monstein of the Institute for Astronomy of the Swiss Federal Institute of Technology Zurich (ETH Zurich),
record the intensity of
electromagnetic radiation at radio frequencies, between 45 and 870 megahertz.