Last year, astronomers revealed a stunning image showing a ring of matter swirling around a supermassive black hole, and a dark hole in the ring representing the black hole’s “shadow.”
That iconic image of the black hole represents a week of observations taken in 2017 by the Event Horizon Telescope (EHT), an array of eight telescopes spread across the world, linked together to increase their resolving power.
However, that array was put together over many years, and during that period the black hole was observed by the not-quite-complete EHT many times. While the data weren’t sufficient to create images, they could be analyzed to look at the material around the black hole to look for anything that might change over that time.
A team of astronomers tackled this hefty project, and found two important things: The size of the ring and the “shadow” didn’t change, but the brightness of the ring did. Not only that, where it was brightest changed, too, and it’s not clear why.
A year in the life of M87*, the supermassive black hole in the galaxy M87. The first part shows complicated simulations of the hot material orbiting the black hole using the math of General ...