One of the mathematical outcomes of Albert Einstein’s Theory of General Relativity is that an object with sufficiently high density will have such strong gravity that nothing, not even light, can escape. This is a ‘black hole.’
There is strong scientific evidence that there is a supermassive black hole at the center of most galaxies, including the Milky Way galaxy. Until recently, these black holes were studied using indirect techniques. For example, measuring the motion of stars at the center of the Milky Way indicates that an extremely massive, invisible object is present.
On April 10, a consortium of research organizations jointly released the first image of a black hole located at the center of Messier 87. M87 is a galaxy about 55 million light years from Earth. The image is the work effort of more than 200 scientists and years of planning. The Event Horizon Telescope consortium generated the image using 8 radio-telescopes located across the globe.
Combining data from multiple radio-telescopes increases the effective size of the telescope. The EHT is equivalent to a telescope with the diameter of the Earth! The two originators of this process were awarded the 1974 Nobel Prize in Physics.
The data collected in 2017 for the first image from the EHT is enormous, about 350,000 gigabytes PER FACILITY. The EHT team found that it was faster to ship the hard drives from each of the installations than to transmit the data electronically. The data were analyzed over two years at central facilities in Germany and Massachusetts.
The EHT team now estimates the mass of M87’s central black hole at 6.4 billion times the mass of our Sun. By comparison, the black hole at the center of the Milky Way is estimated at “only” 4 million times the Sun.
The EHT team is in the process of analyzing data on the super-massive black hole at the center of the Milky Way galaxy.
Three more telescopes will become part of EHT in by 2020.
Western Slope Skies is produced by members of the Black Canyon Astronomical Society. This episode was written and recorded by Bryan Cashion.
Additional resources:
Press conference covering the release of the image
www.space.com/questions-answered-first-black-hole-image.html
“Einstein’s Shadow” by Seth Fletcher, 2018
