SN 1604, also known as Kepler's Supernova, Kepler's Nova or Kepler's Star, was a Type Ia supernova that occurred in the Milky Way, in the constellation Ophiuchus. Appearing in 1604, it is the most recent supernova in the Milky Way galaxy to have been unquestionably observed by the naked eye, occurring no farther than 6 kiloparsecs from Earth. Before the adoption of the current naming system for supernovae, it was named for Johannes Kepler, the German astronomer who described it in De Stella Nova.
A false-color composite (CXO/HST/Spitzer Space Telescope) image of the supernova remnant nebula from SN 1604
X-ray image of SN 1604 from the Chandra X-ray Observatory
Ophiuchus is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek ὀφιοῦχος (ophioûkhos), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. An old alternative name for the constellation was Serpentarius.
Rho Ophiuchi, shown with a surrounding bluish cloud slightly above a pentagon of stars in Scorpius, with the main band of the Milky Way much further to the left
The constellation Ophiuchus as it can be seen by naked eye
Infrared light view of Rho Ophiuchi molecular cloud complex from NASA
Photo from Rogelio Bernal Andreo of the Rho Ophiuchi molecular cloud complex
