Since V404 Cygni already has a companion – a star on a close, 6.5-day orbit, on which the central black hole is leisurely feasting – the newly discovered third object makes the system a trinary.

In the constellation of Cygnus, some 7,800 light-years from Earth, lurks a real space oddity. There, a black hole in a system named V404 Cygni repeatedly engages in behavior that has simultaneously ...