The Enterprise and the Supernova

A star is about to go supernova (that is, explode) and a planet orbiting it must be evacuated. The starship Enterprise is sent to the planet to pick up some Virginia Tech biology major students on a field trip to observe the local flora and fauna.

The trajectories of the Enterprise, the star, and the planet are shown on the space-time diagram. Assume that the planet is not moving relative to the star. The Enterprise will fly by at a constant velocity past the planet and beam up the students without stopping.

The star goes supernova at space-time point S. The light from the supernova spreads out in both directions along the trajectories shown.

1. At which space-time point, labeled A through H, does the Enterprise arrive at the planet?
2. In the frame moving with Enterprise, at which space-time point is the star when the Enterprise arrives at the planet?
3. In the Enterprise frame, does the Enterprise arrive at the planet before the star goes supernova, or after the star goes supernova? Explain your answer referring to the space-time diagram.
4. In the frame fixed to the planet, does the Enterprise arrive at the planet before the star goes supernova, or after the star goes supernova? Explain your answer referring to the space-time diagram.
5. Do the Virginia Tech students marooned on the planet see the supernova explosion before the Enterprise arrives, or after the Enterprise arrives? Explain your answer referring to the space-time diagram.