[xorbax]

How is it "illuminating the whole star system"?

It seems more likely that it'll act like a non intelligent hunk of rock going through some random trajectory.

It's less silly to declare you'll win the lottery. That has happened many times over - but we're yet to discover that can or has existed outside of Earth. While it's nearly impossible it hasn't happened several times over, it's so far impossible that we've encountered even the crumbiest excuse for life.

I assert that it is silly. We're not indigenous American happening upon European settlers. We're indigenous Americans wandering about the continent harassing mammoths, inventing stories of how it'll go when it happens.

[bsdetector]

A ship approaching a sun will see the objects on the far side illuminated fully, but objects on the near side will be illuminated only on a thin edge, like a crescent moon, because they're looking at the 'back' side of the objects.

By sending out a pulse of light they could not just light up the ship-facing side of objects but also determine their precise location and velocity. Seems like something you'd want to do to not waste your thousand-year mission by accidentally colliding with a dark object.

The Wow! signal could be just such an event.

Aliens might use some type of scanning beam rather than a big flash, but I doubt we have the 1977 data to differentiate between a beam scanning our area and a solar-system-wide flash.