Galileo was a liar

An actual exchange between myself and one of my coworkers:

Coworker: It’s Friday!

Me: Took long enough. I don’t care what the calendar says, this week felt like it was at least twenty days long.

Coworker: I hear ya, at least the sun is out today.

Me: Yeah, it’s always nice when the friendly neighborhood star comes around for a visit.

Coworker: The sun isn’t a star, is it?

Me: *stunned silence* (I try to keep the incredible feelings of incredulity and bemusement from showing in my expression) *after a moment’s hesitation* Yes, I’m pretty sure it is.

Coworker: What? No, it can’t be, it’s way too bright.

Me: Then what is it?

Coworker: *rolls eyes* It’s a sun.