From NASA:
M82 X-1 is the brightest X-ray source in Messier 82, a galaxy located about 12 million light-years away in the constellation Ursa Major. While astronomers have suspected the object of being a midsize, or intermediate-mass, black hole for at least a decade, estimates have varied from 20 to 1,000 solar masses, preventing a definitive classification.
Working with Mushotzky and Strohmayer, UMCP graduate student Dheeraj Pasham sifted through about 800 RXTE observations of M82 in a search for specific types of brightness changes that would help pin down the mass of the X-ray source.
As gas streams toward the black hole it piles up into a disk around it. Friction within the disk heats the gas to millions of degrees, which is hot enough to emit X-rays. Cyclical intensity variations in these X-rays reflect processes occurring within the disk.
Scientists think the most rapid changes occur near the inner edge of the disk on the brink of the black hole’s event horizon, the point beyond which nothing, not even light, can escape. With such close proximity to the black hole, the effects of Einstein’s general relativity come into play, resulting in X-ray variations that repeat at nearly regular intervals…..
So that’s what happened to that stock I once bought on a hot tip 🙂
Read more at Rare Midsize Black Hole | Ritholz.com
It is not accurate that nothing can escape from a black hole. Gravity waves can pass through and are measurable to the event. Mass cannot escape, energy cannot escape, force can.
Interesting. I don’t know much about gravity waves. Do they have no mass?