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| The first photo of black hole taken from an Event Horizon Telescope |
Astronomers have just released the very first direct image, ever, of the event horizon of a black hole. Before this, every image of a black hole was a simulation or an illustration. The 'photo' was taken of the supermassive black hole at the centre of a giant elliptical galaxy called M87, around 55 million light-years away. This thing is humungous around 6.5 billion times the mass of the Sun.
It's the first result from the Event Horizon Telescope, a global collaboration that turned radio telescopes around the world into one giant telescope, expressly to find out what a black hole looks like, in real life.
In the middle is the shadow of the black hole. We can't actually see the black hole itself, because it's immense gravity doesn't allow any detectable radiation to escape, so it appears as opaque space.
Around it is the accretion disc. M87's supermassive black hole is active, which means it's surrounded by a tremendous accretion disc of very hot, swirling gas and dust that is slowly falling into the black hole.
Because the disc is rotating, it appears brighter when it is moving towards us, and dimmer when it is moving away. This effect was predicted by Einstein's theory of general relativity. Though the rotation speed hasn't been measured yet EHT claim that it is indeed rotating in a clockwise direction.
