By Ron Cowen
A chance eclipse has enabled astronomers for the first time to measure the width of a disk of swirling, hot matter around a supermassive black hole.
The black hole lies at the center of the galaxy NGC 1365, some 60 million light-years from Earth. Scientists have proposed that gas and dust surrounding such a hole don’t simply fall in but form a rotating disk. Matter dragged inward from the disk would be heated to millions of kelvins and emit X rays before disappearing into the hole.