What you’re seeing is V404 Cygni, a binary system consisting of a star and a black hole. It has remained quiet for the last 25 years, but a week ago, NASA’s Swift satellite noticed a burst of new activity.
This is exciting. If everything goes well, we may get the first-ever photo of a black hole really soon. A large number of astronomers are getting ready to achieve this feat using a global network of telescopes: