(Type Ia supernova observed in 1604 by Johannes Kepler)
Kepler's Supernova (SN 1604)
was a supernova observed by Johannes Kepler in the year 1604,
the most recent confirmed supernova in the Milky Way visible
without a telescope, which was visible during the day for
over three weeks.
It has been determined to be a Type Ia supernova and
the supernova remnant (Kepler SNR) is much studied.