"The most massive known black hole in the universe has been discovered, weighing in with the mass of 18 billion Suns. Observing the orbit of a smaller black hole around this monster has allowed astronomers to test Einstein's theory of general relativity with stronger gravitational fields than ever before.
The black hole is about six times as massive as the previous record holder and in fact weighs as much as a small galaxy. It lurks 3.5 billion light years away, and forms the heart of a quasar called OJ287. A quasar is an extremely bright object in which matter spiralling into a giant black hole emits copious amounts of radiation."
So there may be much larger ones that have already been discovered but which they aren't able to weigh accurately.
ReplyDeleteI wonder how far the event horizon extends on a black hole that big.
Yes, there probably are much larger ones. You can calculate the event horizon with the Schwarzschild radius. My quick calculation says 50 billion km (8 million Earth radi).
ReplyDeletePluto is at 7 billion km from the Sun at aphelion.
ReplyDeleteThat's big :)
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