October 17, 1604German astronomer Johannes Kepler observes a supernova in the constellation Ophiuchus.
Supernova 1604, also known as Kepler's Supernova, Kepler's Nova or Kepler's Star, was a supernova that occurred in the Milky Way, in the constellation Ophiuchus. As of September 2011, it is the last supernova to have been unquestionably observed in our own galaxy, occurring no farther than 6 kiloparsecs or about 20,000 light-years from Earth. Visible to the naked eye, it was brighter at its peak than any other star in the night sky, and all the planets (other than Venus), with apparent magnitude −2.5. It was visible during the day for over three weeks.