This discovery is the clinching evidence that a population of massive stars has exploded in the centre of M82. One area in which interferometry has let to great advances is in the study of cosmic jets. Large amounts of matter are seen to be gushing into space from the cores of certain active galaxies. The jets are very narrow, and they issue from a very small region at the heart of the galaxy. Hundreds of jets are now known.
Some jets are thin and straight, others are wide and billowing.
VLBI observations made over several years appear to show that some jets move faster than light. This is a geometrical illusion that nonetheless confirms that matter in the jets is moving very close to the speed of light. Although there is still much work to be done in understanding these jets, astronomers suspect that they may be issuing from giant black holes in the centres of the galaxies. Interstellar gas is being drawn towards the black hole like bathwater spiralling down a plug hole, heated to tremendous temperatures and then shot out in opposite directions in two narrow jets close to the speed of light.