In the final scene from The Last Jedi, we see a boy, Temiri Blagg (aka "Broom Boy") look up into the starry night sky. He witnesses a streak of light occur high in the heavens, but I always thought this was simply a shooting star.
However, I was reading a review of the film's soundtrack when the writer stated:
One of the children (...) looks up to see the Millennium Falcon go to light speed
Which leads me to wonder, do we know for sure what that was?
Was it a shooting star? The Millennium Falcon? Some other ship? etc.
Video footage of the scene in question (best quality I could find):