# Measurement of the spin of the M87 black hole from its observed twisted light

@article{Tamburini2019MeasurementOT,
title={Measurement of the spin of the M87 black hole from its observed twisted light},
author={F. Tamburini and B. Thid'e and M. D. Valle},
journal={Monthly Notices of the Royal Astronomical Society},
year={2019},
volume={492}
}
• Published 2019
• Physics
• Monthly Notices of the Royal Astronomical Society
• We present observational evidence that light propagating near a rotating black hole is twisted, i.e., carries orbital angular momentum (OAM). Using wavefront reconstruction and phase recovery techniques, we extracted the OAM spectra from ${\lambda=1.3}$ mm radio intensity data collected by the Event Horizon Telescope from around the black hole M87*. The twisted-light/OAM method, complementary to black-hole shadow circularity analysis, allows a direct probing of Kerr metrics and shows that the… CONTINUE READING