The Shadow of M87's Black Hole
A black hole's shadow is about 2.6 times as wide as its horizon, so its size in a telescope weighs the hole, and the 2019 picture of M87* matched 6.5 billion Suns.
What is and is not to scale.
How this was made and sources
One HTML file: no libraries, no network requests. Every number below was read on the date shown, from the page named next to it.
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