April 22, 2019 (HP137).  Until last week, the evidence for black holes had been obtained indirectly, for example by measuring the black hole’s gravitational effect on the path of other celestial bodies and more recently by detection of gravity waves from the collision of black holes using the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 (Nobel Laureate Dr. Weiss presented a seminar on that discovery at the recent Applied Superconductivity Conference in 2018). However, very excitingly for our superconducting community, a black hole has now been imaged using superconducting detectors at radio astronomy observatories around the world in a remarkable and common-culture captivating discovery.

This mapping of the gas ring swirling around and violently captured by the black hole also provided further confirmation of Einstein’s theories on relativity and enabled astronomers to measure its mass (6.5 billion times heavier than our own sun!). This feat is remarkable on many levels. The black hole was chosen for imaging because it had the clearest sight-lines from earth, yet it is 55 million light years, or three hundred quintillion miles away. The imaged gas emission ring surrounding the black hole’s event horizon is only on order of the size of a single star. And as if the task couldn’t get more challenging, the electromagnetic signal that transverses the heavens is attenuated and distorted by gas clouds and ionized particles along its 55-million-year journey.  While it took an international cast of scientists and engineers working together to accomplish this feat, this discovery could not have been accomplished without the heart of the telescope- the Superconducting Insulating Superconducting (SIS) detectors that first greeted each photon after its long journey through the heavens.

Fig.1. (Picture of an NRAO-UVA Band6 ALMA receiver.

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