Black hole surprises
Figure 1. An artist’s drawing of a black hole named Cygnus X-1. It formed when a large star caved in. This black hole pulls matter from a blue star beside it. Credits: NASA/CXC/M.Weiss
What are black holes?Black holes are formed when a star dies. But it must be a heavy star, 5-10 times heavier than … More “Black hole surprises”