| The galaxy's gravity bends the light into different paths, so astronomers see the background blazar as dual images. |
| In early April, the blazar Markarian 421 had an episode of extreme activity, brightening by more than 50 times its typical level. |
| The finding shows that whatever is driving blazar jets operates right near the central black hole, which can weigh in at millions or billions of times the mass of the sun. |
| To match the amount of energy given off by a typical blazar in one second, the sun must shine for 317,000 years. |
| What makes a blazar so bright is that one of these particle jets happens to be aimed almost straight at us. |
