The 17th century must have been an exciting time to be an astronomer, what with so many things in the universe still undiscovered. However, technology at the time would have made it an uneventful time, as well. That is, until 1670, when European astronomers observed a brand new star in the sky, so bright it could easily be seen with the naked eye. The event, which came to be known as Nova Vulpeculae 1670, is said to have burned brightly for two years, then vanished without a trace. Some 340 years later, astronomers have finally solved the puzzle - Nova Vulpeculae 1670 wasn't a nova at all.
“For many years this object was thought to be a nova, but the more it was studied the less it looked like an ordinary nova — or indeed any other kind of exploding star,” said Tomasz Kamiński of the ESO and the Max Planck Institute for Radio Astronomy, Bonn, Germany.