[fhars]

I fear you don't actually undestand several core concept of special relativity, among these past, present, causality and simultaneity. Of these, only the last one is relative to the reference frame. Temporal ordering of events is absolute for events that are causally related, if event A is in the past of event B, which is defined as event B being able to observe event A or any of its consequences, then event A happens before event B in every frame of reference. Only the time difference between A and B depends on the frame of reference (for an observer at rest relative to the microwave background, there are 21 million years between the supernova and our observation of it, but a neutrino emitted by the nova passes though the earth only moments after it was created in its own reference frame, as it travels almost at the speed of light relatie to the nova and the earth). Likewise, we say that B is in the future of A if B can observe A or any of its consequences.

Only in the case that neither A can observe B nor B can observe A, which we denote by saying that the events are in their relative present, the ordering becomes relative to the frame of refrence, but that case is irrelevant in the present discussion, as we can observe the nova and so have established the fact that it (or at least its beginning) is in our past. Note that its maximum, which is predicted to be observable around next friday, is in our present (we can not influence nor observe it yet), while our observation of it is in our future (we can still make plans for where to watch it), at least until next friday, when both of these events simultaneously move into our past.