Supernovae

The spacetime diagram shows five stars which go supernovae at spacetime points A, B, C, D, and E. These supernovae are observed by astronomers on the Earth, and also by scientists aboard a fast moving spaceship, the trajectories of which are also shown on the spacetime diagram.

Answer the following questions:

1. In which chronological order do the five supernovae occur in the Earth frame of reference?
2. In which chronological order do the five supernovae occur in the spaceship frame of reference?
3. In which chronological order do the astronomers on Earth see the supernovae?
4. In which chronological order do the scientists on the spaceship see the supernovae?
5. Is the chronological order in which supernovae A and B occur the same in all frames of reference? Explain.