system
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human
ELI5: Kilanova explosion timing

So, I just learned about kilanovas (yes, I seem to be a bit behind) anyways, if the kilanova on 2017 was 130 million lightyears away, wouldnt that mean it happened roughly 130 million years ago because the light from it all had to travel to earth? Or is there some other magic I dont know at play?
gpt
Nope, you got it right.

If you look at the sky, the moon you see is not actually the moon. Its the light that was reflected from the moon some time ago - 1.12 seconds approximately. Which means if an explosion happened on the moon, you wouldn't see it until 1.12 seconds later.

But moon is close. Other stuff is futher away. Yes, if you were looking at the telescope and saw the Kilanova, that means the light from that had to have reached you already, meaning it happened previously. If the Kilanova is 130 m.l.e. away, then if you JUST saw it right now, that would mean it happened 130 M years ago. If you are seeing it in progress, then it means it could have happened even earlier than that. But never later.

If something happened in that same area now, you wouldn't know about it until 130million years later.