Precovery

In astronomy, the person who first sees an object isn't necessarily the person who gets credit for discovering it. The discoverer is the one who recognizes it as something new or different. If you think it's a star, but someone else figures out it's a planet, you'll be lucky to get a footnote for "precovery" in a chapter about someone else's discovery. Usually, only a few years pass between precovery and discovery. But in one case, several astronomers saw an object and called it a star for more than two centuries before someone realized what it really was.