Nope. The friend is wrong. The planet (who's identifier number escapes me atm) was nick named Goldilocks because it's orbit is similar in distance to it's star as that of Earth to SOL (our sun).
The Goldilocks zone is the safe distance a planet can orbit to have a suitable potential for life as we know it.
The planet is indeed visible, and scientists have been watching it for 10 years or so before the recent announcement to the public.
Your friend is mistaken. He has that thought confused with a star. Stars emit light. Light travels a distance called light speed. If a star twenty light years away went supernova and died, we wouldn't see the flash in the sky then darkness where it was for twenty years.
Planets aren't like that at all. They either reflect light and show a pattern of steady orbit around their star or they don't simple as that.