How did they actually take this picture? (Very Long Baseline Interferometry)

this video is sponsored by kiwiko more about them at the end of the show this is a picture of the supermassive black hole at the center of our milky way galaxy known as sagittarius a-star the black hole itself doesn't emit light so what we're seeing is the hot plasma swirling around it this is only the second picture of a black hole ever it was taken by the event horizon telescope collaboration the same people who brought you this image of the supermassive black hole at the center of galaxy m87 now their original plan was to image sagittarius a star first since it's in our own galaxy it is 2 000 times closer than m87 star but it's also over a thousand times smaller so from earth it appears only slightly larger than m87 star and there are a number of additional challenges to observing it first of all there is a lot of dust and gas between us and the center of our galaxy so you can't even see it with visible light in this video from the european southern observatory we zoom in on our galaxy's core as we get closer and closer at some point we have to switch over to infrared light which can better penetrate the debris allowing us to see it from earth over the past three decades we've been able to peer into the heart of the milky way and witness something truly amazing a collection of stars zipping around on all kinds of eccentric orbits they go incredibly fast one of the stars was clocked going 24 million meters per second that's 8 percent the speed of light all these stars appear to be orbiting something incredibly massive and compact but this object isn't glowing brightly like a star if you watch closely you can see it flicker now and then this is what we believe to be a supermassive black hole from the motion of the stars around it we can infer that the black hole's mass is about 4 million times that of our sun but all crammed down into a tiny point the singularity anything including light that comes within a short shield radius of this point can't escape and ends up in the singularity so for us to see any radiation from the black hole it must come from further out than this usually from ...