I am looking for a word or phrase that could be used to describe events that happen in at the same time as major historical events. Examples include the darkness that occurred during the crucifixion of Jesus Christ, and the comet that appeared in the sky after the assassination of Julius Caesar. The best I could come up with is omen, but I don't think that is correct.
EDIT: After reading a comment, I see that I failed to describe that I am looking for a word in the context of these events being perceived to be related, as if the comet was some sort of a way to show the importance of what had just happened.
given that it is meant to show the importance of the crucifixion
- please do understand that there is a difference between a coincidence that is attributed meaning by ancient historians (like comets or weather) and a natural occurrence that is related to a historical event (like the Black Plague's effect on class hierarchies, or the weather affecting a military campaign - Napoleon in Russia comes to mind). Omens, or foreboding events describe the former.